To see the other types of publications on this topic, follow the link: Schiff base ligands.
Dissertations / Theses on the topic 'Schiff base ligands'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Schiff base ligands.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Najera, Blanca A. "Schiff base macrocyclic ligands and their complexes." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301827.
Full text
2
Archibald, Stephen James. "Complexes of tripodal and macrocyclic Schiff base ligands." Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/14781.
Full textAbstract:
The synthesis, structures and physical properties of tripodal and macrocyclic Schiff base ligands and their complexes are described. All ligands are synthesised by the condensation of amines with 2,6-diformyl- or 2,6-diacetyl-phenols. The synthesis of a novel dodecadentate tripodal Schiff base ligand, L1H3, is described. Reaction of L1H3 with Ln(ClO4)3 where Ln=La, Pr gives complexes of the form [Ln(L1H3)(H2O)](CIO4)3 and where Ln=Y, [Y(L1H3)](CIO4)3. The single crystal X-ray structures of L1H3 and complexes are described. L1H3 reacts with Gd(CIO4)3 in the presence of Cu(CIO4)2 and N,N-diisopropyl-ethylamine resulting in hydrolysis of the acetal functionality to give a complex of the nonadentate tripodal ligand L5H3, [Gd(L5H3)(H2O)2](CIO4)3, the single crystal X-ray structure of which is described. A similar reaction occurs with Ni(CIO4)2, giving [Ni(L5H3)](CIO4)2, The X-ray structure of which is also described. The preparation of L-H3, a related tripodal nonadentate ligand, is described and the structure determined by single crystal X-ray analysis. Complexes prepared by reaction with M(CIO4)2, M=Ni, Zn, are of the form [M(L2H3)](CIO4)2 and the single crystal X-ray structures show the two complexes are isostructural. The Schiff base macrocycle [L3H4](PF6)2 reacts to form [Cu2L3(CH3CO2)]Br preferentially in the presence of La(CIO4)3 and Cu(CH3CO2)2. The single crystal X-ray structure is described. A template condensation of 2,6-diformyl-4-methylphenol and tris(2-amino-ethyl)amine around yttrium(III) yields a complex of the macrobicyclic ligand. L6H3, [Y(L6H3)(H2O)2](CIO4)3, the single crystal X-ray structure of which is described. [La(L6H3)(H2O)](CIO4)3 was further reacted with Ni(CIO4)2 in the presence of N,N-diisopropylethylamine to form the heterobimetallic complex [LaNi(L1)(H2O)](CIO4)2, the structure of which was confirmed by single crystal X-ray analysis. Preliminary magnetic studies on the complex [GdNi(L1)](CIO4)2 indicate a weak ferromagnetic coupling between the metals.
3
Crook, B. V. "A study of homobinuclear and heterobinuclear Schiff base complexes." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376081.
Full text
4
Jakubovic, David Andrew. "Metal complexes of water-soluble multidentate Schiff base ligands." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47487.
Full text
5
Marrs, Deborah Jane. "Macrocycles, macrobicycles : a study." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257447.
Full text
6
Low, May Lee. "Synthèse, caractérisation et bioactivité de ligands issus de bases de Schiff dérivées de dithiocarbazate et de leurs complexes métalliques." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066148/document.
Full textAbstract:
Il y a de nos jours un besoin urgent de découvrir de nouveaux médicaments pour relever le défi de la multirésistance dans le traitement des infections bactériennes et le cancer. Dans cette perspective, des bases de Schiff dérivées de dithiocarbazates et leurs complexes métalliques correspondants sont des candidats intéressants puisqu'ils peuvent être facilement synthétisés et permettent une grande diversité de coordination. Dans cette étude, des complexes tetradentes et bidente ont été préparés. Les ligands et complexes synthétisés ont été entièrement caractérisés par différentes méthodes spectroscopiques et physico-chimiques dans le solide et en solution. L'activité antibactérienne de ces complexes a ensuite été étudiée et a permis de sélectionner un complexe " leader " (plus efficace, stable et fonctionnalisable). Ce complexe a alors été modifié afin d'augmenter sa stabilité en milieux biologique, sa solubilité dans l'eau ainsi que son activité. Il a été conjugué avec différentes entités : des peptides pénétrants, un polyéthylène glycol (PEG) et un peptide inhibiteur des pompes d'efflux bactériennes. Ces complexes ont montré une remarquable activité antibactérienne sur neuf souches de bactéries Gram-positives et Gram-négatives et en particulier, ils se sont avérés très efficaces contre S.aureus. L'activité anti-cancéreuse des complexes non-conjugués a également été étudiée et les complexes de cuivre sélectionnés et testés sur des cellules de cancer du sein ont montré une cytotoxicité élevée. Ceci met en évidence la pertinence d'utiliser les complexes métalliques, pour à la fois stabiliser les ligands et générer des composés plus actifsThere is an urgent need to discover new drugs with novel mechanisms of action, higher activity and improved selectivity to address the severe challenge of multidrug resistance in treating bacterial infections and cancer. In view of this, Schiff bases derived from S-substituted dithiocarbazate and their corresponding metal complexes with a plethora of potentially exciting biological activities and coordination chemistry are attractive candidates. Metal complexes of tetradentate NNSS and bidentate NS ligands have been prepared. The compounds were fully characterized with various physico-chemical and spectroscopic methods in solution and solid state. Conjugation of the most promising antimicrobial compound to various moities (polyarginine, polyethylene glycol (PEG) and an bacterial efflux pump inhibitor) was achieved to prepare improved therapeutic agents. The nanoarginines (R9) derivatives showed the most encouraging synergistic effect upon conjugation and complexation to copper ion with enhanced water solubility, bacteria cell membrane permeability and bioactivity. The Cu(II) R9 derivatives possess remarkable antibacterial activity against a wide spectrum of bacteria and in particular, highly efficacious against S. aureus. This show that the conjugation of polyarginine to dithiocarbazate compounds can greatly influence their therapeutic potential. Cytotoxic assay was also carried out for selected non-conjugated compounds. All the selected Cu(II) complexes assayed against breast cancer cells lines exhibited good cytotoxicity. This work highlights the relevance of the strategy that consists of using metal complexes to stabilize the ligands and improve their bioactivity
7
Zhang, Zhi-Yong. "Synthèse, propriétés structurales, magnétiques et redox de complexes polynucléaires du manganèse avec des ligands à sites donneurs N2O3." Toulouse 3, 1994. http://www.theses.fr/1994TOU30102.
Full textAbstract:
Les travaux realises au cours de cette these ont pour but de modeliser le centre actif de la metalloproteine a manganese du photosysteme ii vegetal. Pour ce faire, nous avons prepare et etudie deux familles de complexes incorporant des bases de schiff pentadentees a sites donneurs n#2o#3 comme ligands binucleants. Parmi les dix neuf complexes prepares, nous avons determine la structure moleculaire d'un complexe dinucleaire du mn(iii), de trois complexes tetranucleaires mn(ii)#2mn(iii)#2 et d'un complexe tetranucleaire mn(iii)#4, par diffraction des rx. Dans la premiere partie de notre travail, les ligands de type 1,3-bis(z-salicylideneamino)propane-2-ol ont conduit a six nouveaux complexes polynucleaires du mn(ii) et trois nouveaux complexes du mn(iii) dont deux sont binucleaires. La deuxieme partie concerne l'etude des complexes du manganese avec les ligands de type 1,5-bis(z-salicylideneamino)pentane-3-ol. En milieu rigoureusement anaerobe, les complexes precurseurs de cette deuxieme serie, mn#i#i#2(l#2)(-oac)#n, reagissent avec le methanol pour conduire a des especes tetranucleaires a valence mixte mn(ii)#2mn(iii)#2 et, pour certains, avec l'eau de melanges methanol/eau ou ethanol/eau pour conduire a des especes tetranucleaires mn(iii)#4. Au cours de ces reactions les deux anions methanolate ou oxo formes sont stabilises sous forme de ligands -3 pontants. Les etudes electrochimiques mettent en evidence l'accessibilite de six etats d'oxydation allant de mn(ii)#4 a mn(iii)#2mn(iv)#2. Associees a la caracterisation des especes bisdinucleaires a valence mixte, elles suggerent que la deuxieme reaction fait intervenir deux etapes successives a deux electrons. L'etude et l'interpretation des proprietes magnetiques de ces complexes par rpe et variation thermique de la susceptibilite magnetique ont permis d'approfondir la connaissance des correlations magneto-structurales dans les edifices polynucleaires du manganese
8
Pop, Mihaela Diana. "Symmetrical and asymmetrical Salen-type Schiff-base ligands and their transition metal complexes." Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408061.
Full text
9
Solanki, Nayan Kumar. "The copper chemistry of substituted 2,6-Bis pyrazolyl pyridines and schiff base ligands." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621813.
Full text
10
Bowman, Gary Raymond, University of Western Sydney, of Science Technology and Environment College, and of Science Food and Horticulture School. "Studies of Titanium(IV)complexes of mixed nitrogen and oxygen donor macrocycles and related schiff base ligands." THESIS_CSTE_SFH_Bowman_G.xml, 2002. http://handle.uws.edu.au:8081/1959.7/410.
Full textAbstract:
This work investigated the use of large tetradentate mixed nitrogen and oxygen donor macrocycles as potential ligands for titanium(IV).These large ligands are capable of encapsulating the metal ion, thereby protecting it from reacting further. In addition, titanium complexes of this type had not been reported previously.Molecular modelling was utilised to evaluate and predict the coordinating potential of the macrocycles investigated.An alternative synthetic strategy was needed to achieve coordination complexes with titanium. This involved the use of a benzene based solvent system and rigorously dry reaction conditions.The final part of the work involved a detailed study of the kinetics of the hydrolysis of the titanium complexes investigated.Doctor of Philosophy (PhD)
11
Zhang, Jie. "Synthesis, characterization and photophysical properties of metal complexes with schiff-base and prophyrin ligands." HKBU Institutional Repository, 2012. https://repository.hkbu.edu.hk/etd_ra/1423.
Full text
12
Shaibu, Rafiu Olarewaju. "A bioinorganic study of some cobalt(II) Schiff base complexes of variously substituted hydroxybenzaldimines." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1006009.
Full textAbstract:
Syntheses of Schiff bases were carried out by reacting salicylaldyhde, ortho-vanillin, para-vanillin or vanillin with aniline, 1-aminonaphthalene, 4- and 3-aminopyridine, and also with 2- and 3-aminomethylpyridine. The various Schiff bases obtained from the condensation reaction were reacted with CoCl₂.6H₂0, triethylamine stripped CoCl₂.6H₂0 or Co(CH₃COO)₂ to form cobalt(Il) complexes of ratio 2:1. The complexes obtained from cobalt chloride designated as the "A series" are of the general formulae ML₂X₂.nH₂0 , (L = Schiff base, X = chlorine) while those obtained from cobalt acetate or triethylamine stripped cobalt chloride denoted as "B" and C" are of the general formulae ML₂. nH₂0. The few complexes that do not follow the general formulae highlighted above are: IA [M(HL)₃.Cl₂], (L = N-phenylsalicylaldimine), 4A = (MLCl₂), (L = N-phenylvanaldiminato), 7 A and 21 A (ML₂), (L = N-naphthyl-o-vanaldiminato, and N-methy-2-pyridylsalicylaldiminato respectively), 8A = MLCI, (L = N-naphthylvanaldiminato), 12A = M₂L₃Cl₂, (L = N-4-pyridylvanaldiminato), 15A (MLCI), (L = N-3-pyridyl-o-vanaldiminato). The ligands and their complexes were characterized using elemental analyses and cobalt analysis using ICP, FT-IR spectroscopy (mid and far-IR), NIR-UV/vis (diffuse reflectance), UV/vis in an aprotic and a protic solvents, while mass spectrometry, ¹HNMR and ¹³CNMR, was used to further characterized the ligands. The tautomeric nature of the Schiff bases were determined by examining the behaviour of Schiff bases and their complexes in a protic (e.g. MeOH) and non-protic (e.g. DMF) polar solvents. The effects of solvents on the electronic behaviour of the compounds were also examined. Using CDCl₃, the NMR technique was further used to confirm the structures of the Schiff bases. The tentative geometry of the complexes was determined using the spectra information obtained from the far infrared and the diffuse reflectance spectroscopy. With few exceptions, most of the "A" series are tetrahedral or distorted tetrahedral, while the "B + C" are octahedral or pseudooctahedral. A small number of complexes are assigned square-planar geometry owing to the characteristic spectral behaviour shown. In order to determine their biological activity, two biological assay methods (antimicrobial testing and brine shrimp lethality assay) were used. Using disc method, the bacteriostatic and fungicidal activities of the various Schiff bases and their respective complexes to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa as well as Aspergillus niger, were measured and the average inhibition zones are tabulated and analysed. Both the Schiff bases and their complexes showed varying bacteriostatic and fungicidal activity against the bacteria and fungus tested. The inhibition activity is concentration dependent and potential antibiotic and fungicides are identified. To determine the toxicity of the ligands and their corresponding cobalt(II) complexes, brine shrimp lethality assay was used. The LD₅₀ of the tested compounds were calculated and the results obtained were tabulated for comparison.
13
Stetsiuk, Oleh. "Homo- and heterometallic 3d-metal complexes with N- and N,O-donor ligands : synthesis, structure and properties." Thesis, Angers, 2018. http://www.theses.fr/2018ANGE0021/document.
Full textAbstract:
Cette thèse est consacrée à la synthèse de complexes 3d homo et hétérométalliques avec des ligands bases de Schiff ou dérivés de la 1,2,4,5-tétrazine, à l’investigation de leur structure et de leurs propriétés physico-chimiques. Ce travail peut être divisé en trois parties. Dans la première partie, nous nous sommes principalement concentrés sur les ligands bases de Schiff, dérivés du salicylaldéhyde et des aminoalcools, formés in situ. Treize complexes hétérométalliques ont été obtenus et entièrement caractérisés. Il a été montré que les composés synthétisés possèdent une activité catalytique dans la réaction de l’oxydation photochimique de l’eau, présentent des propriétés de photoconductive dans les polymères composites et peuvent être utilisés pour le développement de matériaux multifonctionnels. La deuxième partie décrit la fonctionnalisation des ligands base de Schiff par l’introduction dans leur structure des unités tétrathiafulvalène et métaux dithiolènes électroactives. Deux nouvelles familles de ligands ont été synthétisées et caractérisées. La série de sels de radicaux cations et de complexes dithiolènes homo et hétérométalliques ainsi que leurs propriétés physiques ont été discutées. La dernière partie est consacrée aux ligands à base de tétrazine. Les principaux avantages du noyau tétrazine ont été discutés. Deux nouveaux ligands dérivés de la picolylamine et leurs complexes 3d mono- et binucléaires ont été décritsThe thesis is devoted to the synthesis of homo- and heterometallic 3d-metal complexes with Schiff base ligands or derivatives of 1,2,4,5- tetrazine, together with the investigation of their structural and physico-chemical properties. This work can be divided in three parts. In the first part we have been mainly focused on the Schiff base ligands, derivatives of the salicylaldehyde and aminoalcohols. Thirteen heterometallic complexes were obtained and fully characterized. It has been shown that the synthesized compounds possess catalytic activity in the photochemical water oxidation, exhibit photoconducting properties in polymeric composites and can be used for the development of multifunctional materials of wide use. The second part describes the functionalization of Schiff base ligands by the introduction into their structure of electroactive tetrathiafulvalene and dithiolate moieties. Two new families of ligands were synthesized and characterized. The series of radicalcation salts and homo- and heterometallic dithiolene complexes together with the investigation of their physical properties have been described. The last part is devoted to the tetrazine based ligands. The main advantages of the tetrazine ring have been discussed. Two new ligands, derivative of picolylamine and their mono- and binuclear 3d-metal complexes are reported. In conclusion, perspectives of further research related to the described results were highlighted
14
Lalehzari, Azadeh. "Preparation of chiral acid-functionalized Schiff-base ligands and their complexation with divalent transition metals : the story of Helices and Cubanes." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/422.
Full text
15
Lingga, Novalina. "Syntheses and structural studies of polynuclear copper (II) complexes of Schiff-base macrocycles and related ligands." Thesis, University of Canterbury. Chemistry, 1996. http://hdl.handle.net/10092/7315.
Full textAbstract:
Two diimine-diamine ligands derived from the [2+1] template condensation of 1,3-diaminopropane with 2,6-diformyl-4-R-phenol [R = Me, (L¹)-; R = tBu, (L⁸)-], have been isolated as their dicopper(II) hydroxo-bridged complex cations. The ring-closure condensation reaction of the dicopper complex cation of (L¹)- with 2,5-diformylfuran produced a new asymmetric tetraimine macrocycle, (L³)- as the methoxo-, hydroxo- and
ethoxo-bridged dicopper(II) complexes. The hydroxo- and ethoxo-bridged dicopper(II) complexes of (L³)- were isolated from the recrystallisation of the methoxo-bridged analogue using N,N-dimethylformamide, in the absence or presence of ethanol, respectively. The structures of the dicopper(II) acyclic complexes of (L¹)- and of the
ethoxo-bridged complex of (L³)- have been determined by X-ray crystallography.
Two hexacopper(II) complexes of a new acyclic Schiff-base ligand, derived from the [3+2] condensation of 1,3-diamino-2-hydroxypropane with 4-t-butyl-2,6-
diformylphenol, were isolated. Preliminary X-ray crystallographic investigations on these hexacopper(II) complexes revealed a CU₆ ring templating the ligand such that the primary amine groups are held in an appropriate orientation and separation for ring-closure with a dicarbonyl compound.
Two tetracopper(II) macro cyclic complexes were obtained from the [2+2] template condensation of 1,5-diarnino-3-hydroxypentane and 2,6-diformyl-4-
Methylphenol. One of the complexes was isolated as a tetrafluoroborate complex, while the other as a formate complex. The formate complex, whose crystal structure has been determined, is believed to have been generated by the hydrolysis of N,N-dimethylformamide at room temperature, promoted by the tetrafluoroborate complex. The tetrafluoroborate complex underwent dimerisation to give an octacopper(II) complex.
Another tetracopper(II) complex was synthesised by the template condensation of 1,5-diamino-3-hydroxypentane and 2,6-diformyl-methylphenol. X-ray structure determination of this complex revealed that it is a dimer of two dinuclear macro cyclic complexes. The two copper(II) ions in one unit of the dimer are bound inside the macro cycle "laterally". In contrast, two copper(II) ions are found to be held "diagonally" within the cavity of another Schiff-base macrocycle, derived from the [2+2] template condensation of 2,6-diformyl-4-methylphenol with triethylenetetramine.
16
Bowman, G. R. "Studies of titanium (IV) complexes of mixed nitrogen and oxygen donor macrocycles and related Schiff base ligands /." View thesis, 2002. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030721.114851/index.html.
Full text
17
Maxim, Catalin. "Structures étendues et discrètes dans la chimie de coordination en utilisant des ligands type base de Schiff tridentates et cyano bis-phosphonates." Phd thesis, Université d'Angers, 2009. http://tel.archives-ouvertes.fr/tel-00483982.
Full textAbstract:
La thèse présente de nouvelles stratégies dans la chimie métallo-supramoléculaire en utilisant, (1) des nouveaux précurseurs de cuivre (II) avec des positions basales accessibles, qui peuvent favoriser l'échange magnétique, et qui présentent aussi des sphères de coordinations flexibles pour l'obtention des matériaux magnétiques et photo magnétiques; (2) des ligands cyano-bisphosphonates pour l'obtention de réseaux étendus en utilisant la stratégie building-block; (3) des ligands tris-phosphonato-triazine pour l'obtention des complexes avec des centres paramagnétiques Cu(II), Mn(II) et Co(II) en utilisant des fragments M(hfac)2 (hfac = hexafluoro-acétylacétonate). Des nouveaux clusters hétérométalliques ont été obtenus en utilisant comme building-block [Co(CN)6]3-[Cr(CN)6]3-,[Mo(CN)8]4-, [W(CN)8]4- et précurseurs de cuivre (II), synthétisés à partir d'une base de Schiff tridentate qui peut permettre l'accès du connecteur dans le plan basal. Nous présenterons dans la thèse les résultats obtenus avec le ligand 1-Cyanométhylène-bis(5,5-diméthyl-2-oxo-1,3,2-dioxaphosphorinane ). Une série de complexes homométalliques a été synthétisée et caractérisée à l'état solide par diffraction des rayons X sur monocristal. La réaction de ces unités de construction avec un deuxième centre métallique conduit à des systèmes supramoléculaires étendus.
18
Zhou, Wen-Juan. "Polyamine and Schiff base metal complexes incorporated in mesostructured templated porous silicas : tentative application in selective oxidation." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2009. http://tel.archives-ouvertes.fr/tel-00533599.
Full textAbstract:
De nouveaux matériaux ont été conçus à partir de matériaux hybrides organique-inorganiques mésoporeux renfermant des complexes de Cu(II). Ils ont été mis en œuvre comme catalyseurs dans des réactions d'oxydation sélective. La localisation des sites du métal a été contrôlée en utilisant trois ligands synthétiques le type organosilane et deux stratégies différentes, c. àd.,une synthèse dite "one-pot", et un greffage post-synthètique. Les organosilanes ont été le N-(2-aminoéthyl)-3-aminopropyltriméthoxysilane (L1), le N-propylamine-salicylaldimine-triméthoxy-silane (L2) et le de N-(salicylaldimine)- (N'-propyltriméthoxylsilane)-diéthylènetriamine (L3). En outre, l'ion Ni(II) a été utilisé comme sonde structurale. Selon la synthèse "one-pot", les complexes Ni(II)-L1, Cu(II)-L1 et Cu(II)-L2 ont été co-condensés avec du silicate de sodium en présence d'un tensoactif, le cé-tyltriméthylammonium tosylate. Ce dernier avait le rôle de gabarit structurant pour la cons-truction d'organosilices mésoporeuses périodiques (PMOs), de structure bien ordonnée de type MCM-41. Ces matériaux ont ensuite été soumis à des traitements mis au point pour pré-server la structure mésoporeuse utilisant un mélange de chlorotriméthylsilane et hexaméthyl-disilazane ou une quantité appropriée de HCl aqueux (lavage) pour extraire le tensio-actif. Dans les greffages post synthétiques, les complexes Ni(II)-L1, Cu(II)-L1 ou Cu(II)-L3 ont été liés de façon covalent à la surface de silice mésoporeuse préformée selon une distribution uniforme mettant en œuvre une technique dite de pochoir moléculaire. Une caractérisation multitechnique approfondie fut mener pour vérifier la structure et la morphologie du matériau et pour déterminer le site de coordination du métal (XRD, TEM, isothermes d'adsorp-tion-désorption d'azote, analyse élémentaire, ATG, spectroscopies DRUV, FT-IR et RPE). De plus, l'accessibilité chimique du site métallique et le relargage du métal ont été testés en utili-sant 1) l'isothiocyanate (SCN-) comme ligand sonde, 2) l' échange des ions Ni(II) par les ions Cu (II) d'ions ou encore 3) la résistance à la lixiviation acide. Outre les sites métalliques des canaux obtenus par greffage et trés ressemblant à des sites "en solution", deux autres sites ont été mis en évidence. Ils sont tous les deux situés dans les murs des pores. L'un non accessible, est appelé “site enlisé”, l'autre est “site émergenant”. L'activité catalytique en hydroxylation du phénol par le peroxyde d'hydrogène et oxydation du catéchol par le dioxygène dépend de la localisation du métal. Les complexes Cu(II)-L3 greffés présentent les meilleures activités catalytiques et fonctionnent dans l'eau. La conversion et la sélectivité en produits valorisables comme le catéchol et l'hydroquinone, ont été étudiées en fonction du temps, de la température, du pH et du rapport substrat /oxydant. Enfin, le recyclage du catalyseur a également été étu-dié.
19
Cheng, Wing-kin. "Synthesis, reactivities, and electrochemistry of osmium complexes with macrocyclic tertiary amine and multianionic amide and schiff-base ligands /." [Hong Kong : University of Hong Kong], 1989. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12374118.
Full text
20
Liang, Hongze. "Synthesis, crystal structures and spectroscopic properties of mono- and bi-metallic Schiff-base complexes ; Synthesis of polydentate and macrocyclic phosphine ligands, and their reactivities towards transition and lanthanide metal ions." HKBU Institutional Repository, 2001. http://repository.hkbu.edu.hk/etd_ra/294.
Full text
21
Chotard, Florian. "Ligands Phosphine-diène et Salicylamidines : chimie de coordination, catalyse et thérapie." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCK001/document.
Full textAbstract:
Les travaux de thèse retranscrits dans ce mémoire ont pour sujet l’élaboration de nouveaux ligands pour la coordination de métaux et l’application des complexes correspondants pour la catalyse et la thérapie.La première partie du manuscrit traite de l’élaboration de ligands phosphine-diène, de leurs analogues saturés et des complexes arène-ruthénium correspondants. Le départ d’arène permet au ligand phosphine-cycloheptadiène de former avec le ruthénium un complexe bimétallique cationique où le ligand est chélate κ-P/diène-η4. Ces complexes ont été appliqués en catalyse pour l’addition radicalaire par transfert d’atome (ATRA) de CCl4 au styrène. Lors de l’utilisation de conditions dures, la supériorité des complexes « diène » a pu être mise en évidence par rapport aux analogues saturés.La seconde partie rapporte le développement de nouveaux analogues de base de Schiff : les « salicylamidines ». L’utilisation de différentes voies de synthèse a permis d’obtenir plusieurs générations de ligands. Ils ont été utilisés pour la coordination de métaux et sont particulièrement adaptés à la formation de complexes avec le zinc et l’aluminium. Certains de ces composés ont été utilisés pour la polymérisation par ouverture de cycle (ROP) de lactides et ont démontré une bonne activité.La dernière partie concerne la synthèse et l’évaluation de complexes métalliques comme agents anticancéreux. Des complexes phosphine-or et phosphine-ruthénium ont été synthétisés et évalués pour leur activité antiproliférative. Les complexes phosphine-or présentent une activité remarquable, meilleure que le cisplatine. La nature de l’arène des complexes phosphine-ruthénium influe fortement sur leur activité, les dérivés « benzoate d’éthyle » donnent des cytotoxicités significativement meilleures que les analogues « p-cymène ». Des complexes de titane et de zirconium avec un ligand de type aza-dipyrrométhène ont été synthétisés. Une étude préliminaire de leurs propriétés photophysiques a été réalisée et a indiqué que les composés étaient fluorescents. L’étude de leur propriété anticancéreuse a démontré une faible cytotoxicitéThe subject of this thesis concerns the development of new ligands, their coordination chemistry, and the synthesis of the corresponding metal complexes for catalysis and therapy.The first part of this work relates to the synthesis of diene-phosphine ligands, their saturated analogs, and the corresponding arene-ruthenium complexes. Arene decoordination allows the formation of a cationic bimetallic complex where the ligand is diène-η4/κ-P coordinated to the ruthenium. These complexes have been applied to atom transfer radical addition (ATRA) of CCl4 to styrene. When harsh reaction conditions are used, the superiority of the “diene” complexes is highlighted comparing to saturated analogs.The second part concerns the development of new Schiff base analogs: the “salicylamidines”. Several ligand generations have been obtained following different synthetic paths. They have been used for metal coordination, and are especially well-suited for the formation of zinc and aluminium complexes. Some of the compounds have been applied to ring opening polymerization (ROP) of lactides, and demonstrated good activity.The last part reports on the synthesis and assessment of metal-based anticancer agents. Some phosphine-gold and phosphine-ruthenium complexes have been synthesized and tested for their antiproliferative activity on several cancer cell lines. The phosphine-gold complexes showed impressive activities, better than cisplatine. Activity of phosphine-ruthenium is strongly influenced by the nature of the arene, ethyl benzoate derivatives are significantly more cytotoxic than p-cymene ones. Titanium and zirconium complexes with aza-dipyrromethene ligand were synthesized. Preliminary photophysical study was performed and indicated fluorescence. Their anticancer properties were assessed, and they are only poorly cytotoxic
22
Guidal, Valentin. "Conception et réactivité de nouveaux complexes de lanthanides et de cobalt contenant des ligands rédox-actifs : application aux réductions multi-électroniques." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENV022/document.
Full textAbstract:
La capacité des complexes de lanthanides divalents à promouvoir des réductions inhabituelles suscite actuellement un grand intérêt, tout particulièrement leur aptitude à activer des petites molécules telles CO2 et N2 dans des conditions douces. Les ions lanthanides, de par leurs propriétés de coordination tout à fait uniques pourraient offrir une alternative aux métaux de transition couramment utilisés pour la conception de catalyseurs. Cependant, comparativement aux métaux du bloc d, la chimie de coordination des lanthanides est exclusivement dominée par des transferts mono-électroniques qui impliquent uniquement les capacités rédox du centre lanthanide. C'est pourquoi le développement de nouveaux complexes de lanthanides capables de réaliser des réductions poly-électroniques est particulièrement intéressant. Dans un premier temps, nous avons utilisé des ligands rédox-actifs de type base de Schiff π-conjuguées pour étudier la chimie des ions lanthanides en réduction. Cela nous a permis d'isoler des complexes dans lesquels deux ou quatre électrons sont stockés sur le ligand via la formation de liaisons C-C. Ces mêmes liaisons sont rompues en présence d'agents oxydants et les électrons sont libérés pour réaliser des transformations multi-électroniques. Ce procédé a été observé pour des bases de Schiff tridentates et tétradentates, ce qui nous a permis de moduler les propriétés rédox des composés. La réactivité avec CO2 des complexes synthétisés a également été étudiée et nous avons identifié des complexes de néodyme capables de réduire le CO2. Dans un second temps, nous nous sommes intéressés à l'étude de complexes de cobalt contenant des ligands rédox-actifs de type base de Schiff π-conjuguées capables de stocker des électrons sous forme de liaisons C-C. Ce système, déjà étudié dans les années 1990, avait démontré sa capacité à activer le CO2. Avec l'intention de déterminer l'espèce active dans la réaction avec CO2, nous avons revisité ce système et mis en lumière un équilibre d'isomérie rédox entre un complexe de Co(I) et un complexe de Co(II) où un électron peut être localisé sur le métal ou sur le ligand. Nous nous sommes également intéressés aux paramètres qui régissent cet équilibre. En particulier, nous avons étudié l'influence de l'architecture du ligand sur les propriétés rédox des complexes de cobalt. Ces études offrent de nouvelles perspectives pour le développement de complexes capables d'effectuer la réduction électrocatalytique du CO2The redox chemistry of lanthanide complexes is attracting increasing interest because of the potential of divalent lanthanide complexes to promote unusual redox chemistry. For example they are able to activate small molecules such as CO2 and N2 in mild conditions. Due to the unique coordination and bonding properties of the lanthanide ions, their compounds could provide an attractive alternative to transition metals for the catalytic transformation of small molecules. However, metal-based multi-electron processes remain uncommon in lanthanide chemistry especially in comparison with the d-block metals; the chemistry of low-valent lanthanides being dominated by single-electron transfers. In this context, the first aim of this project was to investigate the association of lanthanides with a redox-active ligand acting as an independent electron reservoir within the same molecule. Accordingly, we examined the use of highly π-delocalized Schiff base ligands to study the reductive chemistry of lanthanide ions. This led to the isolation of electron-rich complexes which are stabilized by storing two or four electrons on the ligands through the formation of C-C bonds. Interestingly, these C-C bonds can be cleaved by oxidizing agents and the electrons released can participate in multi-electron redox reactions. This process was observed within different tridentate and tetradentate Schiff-base ligand scaffolds, allowing a tuning of the properties of the compounds. The ability of these complexes to react with CO2 has been studied, which lead to the identification of some neodymium complexes capable of reducing CO2. The second part of this work was dedicated to the study of cobalt complexes bearing redox-active and highly π-delocalized Schiff base ligands able to store electrons through the formation of C-C bonds. Seminal studies on Schiff base complexes of cobalt had been carried out in the 1990's and they demonstrated the ability of these complexes to activate CO2. With the aim to identify the active species responsible for CO2 activation, we have revisited these systems and highlighted a redox-isomeric equilibrium between a Co(I) and a Co(II) complexes where the electron can be localized on the cobalt or on the ligand. We also investigated the parameters influencing this equilibrium. In particular we have investigated the effect of the ligand architecture on the redox reactivity of cobalt complexes. Such studies pave the way to the development of new complexes for the electrocatlytic reduction of CO2
23
Naidoo, Fayyaadh. "Graphene modified Salen ligands for the electrochemical determination of heavy metal ions." University of Western Cape, 2020. http://hdl.handle.net/11394/7540.
Full textAbstract:
>Magister Scientiae - MScEnvironmental pollution is a major threat to all life, which needs to be addressed. Heavy metals are well-known environmental pollutants due to their toxicity and, persistence in the environment toxicity for living organisms and having a bioaccumulative nature. Environmentally, the most common hazardous heavy metals are: Cr, Ni, Cu, Zn, Cd, Pb, Hg, and As. Remediation using conventional physical and chemical methods is uneconomical and generates waste chemicals in large quantities. This study focuses on the extraction and determination of heavy metals (Nickel, Copper and Cobalt) by chelating Schiff base ligands of the type [O,N,N,O] with these metal ions. Two Schiff base ligands [N,N’-ethylenebis(salicylimine)] (Salen) and ligand [1,3-bis(salicylideneamino)-2-propanol] (Sal-DAP) were synthesized and characterised using FTIR, 1H and 13C NMR spectrometry and GC-MS techniques. Electrochemical detection of heavy metal ions in this work was achieved via ligand-metal complexation via two approaches. The in-situ method in which the metal and ligands were added to the electrochemical cell and stirred to allow complexation to occur and monitored by square wave voltammetry. While the ex-situ approach involved modifying the electrode surface by depositing a thin film of Schiff base on the electrode surface and immersed into a heavy metal solution to allow the complexation. Three modified GCE were used viz. Salen coated GCE, reduced graphene oxide-Salen coated GCE and a nafion-Salen coated GCE. The two approaches used for the electrochemical detection were successful and effective. The ex-situ approach was selected for the modification of the electrode surface since it demonstrated a higher capacity for heavy metal ion extraction.
2021-11-30
24
Mopp, Estelle. "A bioinorganic investigation of some metal complexes of the Schiff base, N,N'-bis(3-methoxysalicylaldimine)propan-2-ol." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1006768.
Full textAbstract:
This thesis includes the synthesis, characterisation, antioxidant and antimicrobial activities of Cu(II)-, Co(II)- and Co(III) complexes with N,N'-bis(3- methoxysalicylaldimine)propan-2-ol, 2-OH-oVANPN. The Schiff base ligand, 2-OHoVANPN, is derived from o-vanillin and 1,3-diaminopropan-2-ol. The o-vanillin condensed with 1,3-diaminopropan-2-ol in a 2:1 molar ratio yields this potential tetraor pentadentate ligand. The complexes synthesized are tetra (or penta or hexa) coordinated. Formation of the complexes is symbolized as follows:- MX₂ + 2-OH-oVANPN (2:1) -> [M(2-OH-oVANPN)Xn] + HnX MX₂ + 2-OH-oVANPN (2:1) -> [Mn(2-OH-oVANPN)OH] + H₂X₂ MX₂ + (o-vanillin : diaminopropanol) (1:1) -> [M(1:1)X₂] MX₂ + (o-vanillin : diaminopropanol) (1:1) -> [M₃(1:1)X₄] M = Cu(II), Co(II) or Co(III); X = Cl; n = 1, 2. Their structural features have been deduced from their elemental analytical data, IR spectral data, and electronic spectral data. With the exception of {Cu₃(C₁₁H₁₄N₂O₃)(Cl)₄(H₂O)₆}(A4), the Cu(II) complexes were monomeric with 2-OH-oVANPN acting as a tetradentate ligand. A binuclear Co(II) complex, [Co₂(C₁₉H₁₉N₂O₅)(OH)] (B1), was synthesised and the rest of the Co(II) and Co(III) complexes were monomeric with chloride ions coordinating to the metal centre in some cases. Electronic data suggest that the cobalt(II) complexes have octahedral geometries and the copper(II) complexes have square planar structures – Co(III) is likely to be octahedral. Thermal analyses, which included the copper-block-method for determining sublimation temperatures, revealed that some copper(II) and cobalt(II) complexes are hygroscopic and sublime at 200 °C and below. DSC analyses of the Cu(II) complexes gave exotherms around 300 °C for complexes K[Cu(C₁₉H₂₀N₂O₅)(OH)]·2H₂O (A1) and [Cu(C₁₁H15N₂O₃)(Cl)₂]·2H₂O (A2) and above 400 °C for [Cu(C₁₁H₁₆N₂O₃)(Cl)₂] (A3) and {Cu₃(C₁₁H₁₄N₂O₃)(Cl)₄(H₂O)₆} (A4). Antioxidant studies were carried out against the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·). The cobalt(II) complex, [Co₂(C₁₉H₁₉N₂O₅)(OH)] (B1), which was synthesized in the presence of KOH, had no antioxidant activity, whilst the other cobalt(II) complexes, [Co(C₁₇H₁₇N₂O₅(Cl))]·1½H₂O (B2), [Co(C₁₉H₂₂N₂O₅) (Cl)₂]·5½H₂O (B3) and [Co(C₁₉H₂₂N₂O₅)(Cl)₂]·5½H₂O (B4), which were synthesised in the absence of KOH, demonstrated antioxidant activity. The latter complexes are candidates for cancer cell line testing, while [Cu(C₁₁H₁₆N₂O₃)(Cl)₂] (A3), {Cu₃(C₁₁H₁₄N₂O₃)(Cl)₄(H₂O)₆} (A4), [Co(C₁₉H₂₁N₂O₅)(Cl)₂ ]·5H₂O (C2) and [Co(C₁₉H₂₀N₂O₅)(Cl)]·3H₂O (C3) may show anticancer activity through possible hydrolysis products. Most of the complexes synthesized displayed antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans. The results indicated that complexes [Cu(C₁₁H₁₆N₂O₃)(Cl)₂](A3), [Co(C₁₉H₂₂N₂O₅)(Cl)₂]·5½H₂O (B3) and [Co(C₁₉H₂₁N₂O₅)(Cl)₂ ]·5H₂O (C2) are active against the Gram-negative Ps. aeruginosa and that the ligand, 2-OH-oVANPN, did not have any activity. The same trend was observed with 2-OH-oVANPN, {Cu₃(C₁₁H₁₄N₂O₃)(Cl)4(H₂O)₆} (A4) and [Co(C₁₉H₂₀N₂O₅)(Cl)]·3H₂O (C3) against the Gram-positive S. aureus. As for activity against E. coli and C. albicans, some complexes showed more activity than the ligand. There is an observed trend here that the metal complexes are more active (toxic) than the corresponding ligand, which is in agreement with Tweedy’s chelation theory.
25
Chan, Ka-ho, and 陳嘉豪. "Ruthenium-N-heterocyclic carbene and ruthenium acetylide complexes supported by macrocyclic porphyrin or tetradentate schiff base ligands : synthesis, structure and catalytic applications." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2015. http://hdl.handle.net/10722/211130.
Full text
26
Olalekan, Temitope Elizabeth. "Synthesis, characterisation and biological activity of 2-(methylthiomethyl)anilines, 2-(methylthio)anilines, their Schiff-base derivatives and metal(II) (Co, Ni, Cu) complexes." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1020868.
Full textAbstract:
A series of 31 sulfur-nitrogen donor ligands and 64 metal(II) complexes have been investigated. The thiomethylated aniline ligands 2–(methylthiomethyl)aniline 2MT and 2–(methylthio)aniline 2MA were synthesized with their substituted derivatives (-Me, -MeO, -Cl, -Br, -NO2) to serve as chelating agents. These ligands behave as bidentate ligands with SN donor group with Co(II), Ni(II) and Cu(II). The Co(II) and Ni(II) complexes have the ML2Cl2 molecular formula while the Cu(II) complexes formed with MLCl2 stoichiometry where L is the bidentate ligand. The ligands and their metal(II) complexes have been characterized by elemental analysis and with spectroscopic techniques. The trend observed in the NMR spectra and IR frequencies of the thiomethylated compounds shows there is a significant difference between the 2MT and 2MA series as a result of sulfur lone pairs extending the conjugation of the aromatic ring in the case of the latter. The effect of the position and electronic nature of ring substituent on the NMR shifts of the amine protons is discussed. The 6- and 5-membered chelate complexes formed by the 2MT and 2MA ligands respectively do not show significant diversity in their spectroscopic properties. From the elemental analysis for the Co(II) and Ni(II) complexes, their compositions reveal 1:2 M:L stoichiometry with 2 chlorine atoms from the respective metal salts. In addition, the spectroscopic data are largely indicative of tetragonally distorted structures for these solid complexes. The X-ray crystallography data reveal the Cu(II) complexes exist as square pyramidal dimers and with long Cu–Cl equitorial bonds fit into the tetragonally distorted octahedral structure. The electrolytic nature of Co(II) and Cu(II) complexes in DMF were found to be similar, they behave as non electrolytes in contrast to Ni(II) complexes which are 1:1 electrolytes. The electronic spectra of these metal(II) complexes were found to be different for both their solid forms and in solutions of DMF and DMSO and this has been discussed. The thiomethylated aniline ligands possess the amine and thioether groups which are present in many known biologically active compounds, hence the biological activity of the ligands and their metal complexes were tested against three strains of bacteria and one fungus. The methoxy-substituted derivatives were found to possess better inhibitory activity and this was similarly reflected in the metal(II) complexes. The activity of the complexes can be said to be in the order, Cu(II) > Co(II) > Ni(II). The Schiff-base derivatives were prepared from the ligands and para-methoxysalicylaldehyde and their Cu(II) complexes were synthesized in order to determine their biological activity. The Schiff-base ligands were found to be less active than their parent ligands. The Cu(II) complexes are not soluble in water, DMSO or DMF, as a result and could not be evaluated for their biological activity. Based on the good results from the antimicrobial evaluation, the antiplasmodial activity of some of the Co(II), Ni(II) and Cu(II) complexes of the thiomethylated ligands against Plasmodium falciparum (FCR-3) was determined. At 50 μM concentration level, the Cu(II) complexes show activity equal or better than the prophylactic chloroquine. The Cu(II) complexes with the methoxy-substituted demonstrated exceptional activity but their Co(II) and Ni(II) analogues did not show any activity. The cytotoxicity of the active Cu(II) complexes at 50 μM concentration was determined against the breast cancer cell line (MDA-MB-231). The compounds destroyed the cancer cell in the range of 28–40%, thus showing their preferred activity against the parasitic cell instead of the cancer cell. The selectivity demonstrated by these compounds have shown them to be potential antimalarial agents and this could be further investigated.
27
Abbott, Mariana Pedrinha. "Modificações oxidativas em proteínas em presença de complexos de cobre(II)." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/46/46134/tde-24102007-104712/.
Full textAbstract:
Neste trabalho alguns complexos diimínicos de cobre(II) com ligantes do tipo base de Schiff, já estudados em nosso laboratório, além de um novo complexo de zinco foram sintetizados e caracterizados por análise elementar, espectroscopias UV/Vis, Infravermelho e de Ressonância Paramagnética Eletrônica (EPR). Estudos sobre a reatividade destes complexos de cobre(II) frente à oxidação de carboidratos por oxigênio molecular foram então realizados. Estes estudos envolveram várias etapas, com variação das concentrações do catalisador, do substrato e do tampão e variação do pH, verificando-se a influência de cada um destes fatores na cinética de reação. Para tentar entender a interação da albumina bovina (BSA) com os complexos diimínicos de cobre(II) estudados, foram realizados experimentos utilizando-se a técnica de dicroísmo circular e espectroscopia eletrônica. A estabilidade termodinâmica relativa dos vários compostos foi assim determinada, estimando-se os respectivos valores das constantes de estabilidade. Experimentos sobre a atividade oxidante destes complexos frente à albumina bovina, causando danos oxidativos à proteína, também foram efetuados, determinando-se a formação de grupos carbonil na proteína, que foram monitorados espectrofotometricamente, através da obtenção das correspondentes dinitrofenil-hidrazonas, pela reação com dinitrofenil-hidrazina (DNPH). Através da técnica de EPR, foram realizados estudos para a detecção e identificação de espécies radicalares na interação da albumina com os complexos de cobre(II) em presença de peróxido de hidrogênio, com o uso de um captador de spin apropriado. Estudos sobre as possíveis interações dos complexos de cobre(II) com a albumina humana (HSA) e com o plasma sanguíneo foram realizados através das técnicas de EPR e SDS-PAGE. Além disso, a reatividade dos complexos de cobre(II) frente a glutationa, um agente redutor presente em alta concentração no citosol, foi investigada através de experimentos de fluorescência. Finalmente, a influência dos complexos imínicos de cobre(II) sobre a respiração mitocondrial foi investigada, já que estes complexos se mostraram indutores eficientes de apoptose frente a diferentes células tumorais. Para este estudo utilizou-se um oxígrafo para monitorar o consumo de oxigênio durante a respiração mitocondrial, em presença dos complexos de cobre estudados.In this work some copper(II) complexes with Schiff base ligands, already studied in our laboratory, have been prepared, as well as a new similar zinc complex. After being characterized, especially by spectroscopic techniques (UV/Vis, IR, and EPR), these complexes had their reactivity as catalysts for the oxidation of carbohydrates by molecular oxygen verified. The influence of different factors on the kinetics of reaction, such as variation of the catalyst concentration, substrate concentration, buffer concentration and pH of the solution, was investigated. In order to understand the possible interactions of the copper(II) complexes studied with the protein albumine, studies using CD and electronic spectroscopies were carried out by adding the copper complexes to bovine serum albumine (BSA), and determining the corresponding relative stability constants for each complex. The activity of such copper complexes as oxidant agents toward the protein was also verified, with the formation of carbonyl groups in the protein observed by monitoring spectrophotometrically the corresponding dinitrophenylhydrazones, after reaction with dinitrophenylhydrazine (DNPH). By using EPR spectroscopy and an appropriate spin scavenger, reactive oxygen species were detected and identified as a result of the oxidative damage to the protein occurring in the presence of the copper complexes and hydrogen peroxide. Interactions of the human serum protein (HSA) and human plasma with the copper complexes studied were verified by EPR and SDS-PAGE techniques. Additionally, the reactivity of these complexes toward the reductive agent glutathione, present in the citosol at high concentration, was investigated by fluorescence measurements. Finally, the influence of the complexes in the mitochondrial respiration was verified, since those compounds are able to induce efficiently apoptosis in the presence of different tumoral cells, monitoring the oxygen consumption with a selective oxygen electrode
28
Tanh, Jeazet Harold Brice. "Metallo-supramolecular Architectures based on Multifunctional N-Donor Ligands." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-39665.
Full textAbstract:
Self-assembly processes were used to construct supramolecular architectures based on metal-ligand interactions. The structures formed strongly depend on the used metal ion, the ligand type, the chosen counter ion and solvent as well as on the experimental conditions. The focus of the studies was the design of multifunctional N-donor ligands and the characterization of their complexing and structural properties. This work was divided into three distinct main parts: The bis(2-pyridylimine), the bis(2-hydroxyaryl) imine and the tripodal imine / amine ligand approach.
In the first part a series of bis(2-pyridylimine) derivatives having different linking elements were employed as building blocks for novel supramolecular architectures. Reaction of individual d-block metal salts with these ligands has led to the isolation of coordination polymers, a metallamacrocycle, double-stranded helicates, triple-stranded helicates as well as of circular meso-helicates. The nature of the spacer in the Schiff base ligands, the noncovalent weak interactions, such as hydrogen bond, face-to-face π-π and edge-to-face CH-π interactions, are all important factors influencing the architecture of the final products.
Topological control of the assembly process of the hexanuclear meso-helicates is clearly associated with the bidentate coordination of the sulfate anion which directs the formation of a double- rather than a triple-stranded helicate around the octahedrally coordinated Cu(II). Surprisingly, the variation of the linker function in the ligands, which significantly changes the linking angle of the pyridylimine strands, has only a little influence of the resulting structure. Also the use of a mixture of ligands does not influence the meso-helicate topology; the result is the symmetrically mixed meso-helicate.
The new iron(II) triple helicate [Fe2(L5)3](PF6)4 14 {L5 = bis[4-(2-pyridylmethyleneimino)phenyl]-1,1-cyclohexane} in its chloride form binds strongly to DNA as confirmed by induced circular dichroism signals in both the metal-to-ligand charge transfer (MLCT) and in-ligand bands of the helicate. The induced CD spectrum gives some evidence that [Fe2(L5)3]4+ interacts with the DNA in a single binding mode, which is consistent with major groove binding.
The cytotoxicity of the new iron(II) triple helicate 14 was evaluated on human lung cancer A549 cells and compared with that of cisplatin and that of the previously reported iron(II) triple helicate [Fe2(L1)3]4+{L1 = bis[4-(2-pyridylmethyleneimino)phenyl]methane}. The first results show some distinguishing features for 14 obviously caused by the existing structural differences of the complexes.
In the second part of the thesis, novel uranyl complexes of the bis(2-hydroxyaryl) imine ligands have been synthesized and characterized. 1D coordination polymers and mononuclear structures were formed. In all complexes a distorted hexagonal bipyramidal coordination geometry around the uranyl centre is observed. The imine nitrogen atoms of the ligands do not bind to the metal centre but interact strongly with the hydroxy group via H-bonding. DFT calculations made with L8 ( α,α’-Bis(salicylimino)-m-xylene) are in good agreement with the X-ray crystal structure data. Liquid-liquid extraction studies involving selected ligands and Eu(III) or U(VI) indicate remarkably high selectivity for U(VI) over Eu(III) at weak acidic pH conditions. We believe that the study made opens up new possibilities for uranyl ion extraction which could be interesting in view of the treatment of nuclear waste.
In the third part of the thesis, a series of multifunctional tripodal ligands with different N-donor centres were used for U(VI) and lanthanide, Nd(III), Eu(III) and Yb(III), binding and extraction. Reaction of these metal ions with selected tripodal ligands afforded complexes which were characterized by ESI mass spectroscopy. The complex composition was found to be 1:1 in all cases. The extraction behaviour of the tripodal ligands towards Eu(III) and U(VI) was studied both in the absence and presence of octanoic acid as co-ligand using the extraction system Eu(NO3)3 or UO2(NO3)2–buffer–H2O/ ligand–CHCl3. These separation systems show a remarkably high selectivity for U(VI) over Eu(III). It is interesting to note that the addition of the octanoic acid to the extraction system leads to high synergistic effects. A series of Eu(III) extraction experiments were done to clarify the composition of the extracted complexes. The results clearly point to the formation of various species with changing composition.
29
Mondal, Kartik Chandra [Verfasser], and A. [Akademischer Betreuer] Powell. "Syntheses, Structures and Properties of f and d-f Complexes using O-vanillin-derived Schiff base Ligands / Kartik Chandra Mondal. Betreuer: A. Powell." Karlsruhe : KIT-Bibliothek, 2011. http://d-nb.info/1014279593/34.
Full text
30
Lamine, Walid. "Étude théorique et expérimentale de la structure et de la réactivité de quelques complexes de coordination de zinc contenant des ligands base de Schiff." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1152/document.
Full textAbstract:
Ce travail a essentiellement porté sur la description et la rationalisation de certaines propriétés des complexes du Zinc contenant des ligands de base de Schiff par le biais d’approches mixtes théorique et expérimentale. La première partie de ce travail concerne la synthèse et la caractérisation d’un nouveau complexe dinucléaire de Zn(II) à ligand base de Schiff tétra-azoté N4. Ce complexe s’auto-assemble en hélice à double brin avec un environnement tétraédrique rarement observé pour l’ion Zn2+ avec ce type de ligand. Ce complexe s’est avéré être thermodynamiquement instable en présence de traces d’eau, subissant ainsi une démétallation rapide. De ce fait, sa réactivité vis-à-vis de l’eau a été étudiée par des mesures spectroscopiques et des calculs DFT. Puis, le mécanisme réactionnel de démétallation a été élucidé pour la première fois et pourrait facilement être généralisé à l’hydrolyse des complexes Zn-sal(ph)en apparentés. Dans la seconde partie, le caractère acide de Lewis, principal facteur de la réactivité/coordination des complexes Zn-sal(ph)en a été étudié au moyen des descripteurs de la DFT-conceptuelle. Une analyse préliminaire a été réalisée sur un prototype modèle à savoir [ZnCl4]2-, et les résultats ont été généralisés aux complexes de Zn-sal(ph)en comportant différents types d’espaceurs diamine (flexible, semi-rigide, et rigide) afin de rationaliser l’acidité de Lewis de ces complexes avec la nature du pont diamine. L’inclusion des densités des états excités par le biais du descripteur dual dit « state specific dual descriptor» a permis de décrire avec succès la réactivité appropriée du complexe choisi. Enfin, la troisième partie de ce travail, est consacré à l’effet dit de « self-interaction » survenue dans la modélisation de la réaction de cyclo-addition du CO2 sur les époxydes catalysée par un complexe Zn-N4 base de Schiff en présence de NBu4X (X=I). Cette erreur menant à des profils énergétiques irréalistes au niveau DFT, a été identifiée et une nouvelle approche théorique a été proposée et développée afin de contourner cette erreurIn this work, we focus our interest on the description and rationalization of some properties of Zinc complexes of Schiff bases schemes through theoretical and experimental approaches. The first study deals with the syntheses and characterization of a novel Zn-N4-Schiff base L= ((±) -trans-N, N’-Bis(2-aminobenzylidene)-1,2-diaminocyclohexane) showing an unexpected self-assembled double-stranded helicate structure , in which zinc atoms are in distorted tetrahedral environments, revealing an M- (R, R) left-handed helicity in its asymmetric unit. This dimer is thermodynamically unstable in presence of water traces and undergoes a rapid demetallation process that is studied by both experimental and theoretical approaches. The reaction is monitored through DOSY NMR analysis, and the theoretical mechanism of the demetallation process is elucidated for the first time using DFT method and which should be easily generalized to the demetallation of N2O2 sal(ph)en Zn complexes. In the second part of this study, the Lewis acidic behavior, the main factor of the reactivity/coordination of Zn-sal(ph)en complexes, is studied using conceptual density functional theory descriptors. This Lewis acidic character is addressed in a first stage to a prototype complex, namely [ZnCl4]2- and the results have been generalized to Zn-sal(ph)en complexes with different diamine bridges through flexible to semi-rigid then to rigid ranges, in order to characterize and rationalize this Lewis acid effect in relation with the nature of the diamine bridge. The inclusion of the electronic excited state densities by the so-called state specific dual descriptor allows us to recover successfully the appropriate reactivity of these chosen complexes. Finally, in the third part, we consider the effect of the « self-interaction » occurring when modeling the cycloaddition of CO2 to epoxide reactions catalyzed via the binary system Zn-N4 Schiff base /NBu4X (X=I). This error leading to unrealistic energy profiles at the DFT level has been identified and a new theoretical approach is proposed and developed to correct this error
31
Fels, Sabine. "Höherkoordinierte Komplexverbindungen des Siliciums, Germaniums und Zinns mit chiralen O,N,O´-Liganden." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-211546.
Full textAbstract:
Aufgrund ihrer Eigenschaften und möglicher Anwendungen werden Siliciumkomplexe mit O,N,O´-Ligandsystemen in der Literatur beschrieben. Jedoch fehlen bisher Untersuchungen zur Strukturaufklärung. Im Rahmen dieser Arbeit wurden zahlreiche Silicium-, Germanium- und Zinnkomplexe mit chiralen O,N,O´-Liganden synthetisiert und strukturanalytisch charakterisiert. Dazu wurden die Liganden durch Kondensationsreaktionen von enantiomerenreinen Aminosäuren mit aromatischen ortho-Hydroxyaldehyden bzw. Acetylaceton hergestellt. Die weitere Umsetzung der Liganden mit Elementhalogeniden der Gruppe 14 führte zu den angestrebten Komplexverbindungen. Alle hergestellten Verbindungen wurden umfassend charakterisiert (NMR-, UV/Vis-, IR-Spektroskopie, Elementaranalyse, Einkristallstrukturanalyse, Drehwert). Quantenchemische Berechnungen an einfachen Modellverbindungen sowie an hergestellten Silicium- und Zinnkomplexen führten zu einem grundlegenden Verständnis der Festkörper-NMR-Parameter dieser Verbindungsklasse.
32
Novoa, Serrano Néstor-Alonso. "Complexes asymétriques de NiII et CuII à ligands base de Schiff tridentates ONO, précurseurs de nouveaux adduits dipolaires push-pull : étude de leurs propriétés optiques non linéaires du second ordre (ONL-2)." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S018/document.
Full textAbstract:
Les précurseurs de ligands base de Schiff électro-donneurs et électro-accepteurs R-ONOH₂ sont préparés par réaction de monocondensation entre les β-dicétones appropriées et respectivement le 1,2- et le 1,2-4-nitro-aminophénol. Ils existent exclusivement sous leurs formes tautomériques céto-énamine en solution et à l'état solide. Dans les complexes correspondants de NiII et de CuII, le métal adopte une géométrie plan carré et est coordiné par les atomes d'azote et d'oxygène du ligand dianionique tridentate et par l'azote du coligand pyridine. L'hyperpolarisabilité quadratique, déterminée par la technique DHL est très élevée. La substitution de la pyridine par la 4,4'-bipyridine conduit systématiquement aux complexes dimériques correspondants. Un composé similaire comportant l'espaceur bis(4-pyridyle)acétylène est formé après réaction de couplage croisé de Sonogashira. Cette même réaction de couplage croisé entre les blocs de construction électrodonneurs et électro-accepteur permettent de préparer le système «push-pull» D-π-A désiré. Les réponses ONL du second ordre des complexes contenant le ligand électro-actif methylène-pyrane peuvent être modulées par bi- (R = An) et tétra- (R = Fc) oxydation réversible avec formation/rupture d'une liaison C-C, constituant ainsi un nouvel exemple de commutateur ONL-2 réversibleElectron donating and electron withdrawing ligand precursors R-ONOH₂ were prepared by monocondensation reaction of the appropriate β-diketones and 1,2- and 1,2-4-nitro-aminophenol, respectively. They do exclusively exist as their enaminone tautomeric form both in solid-state and in solution phase. In their corresponding Schiff base complexes of NiII and CuII, the central metal is tetracoordinated in a square-planar environment. The coordination sphere is formed by the nitrogen and oxygen atoms of the dianionic tridentate ligand and the fourth coordination site is occupied by the nitrogen atom of the pyridine co-ligand. The derivative exhibited a high quadratic hyperpolarizability (β1.91) determined by the HLS technique. Substitution of 4,4’-bipyridine for pyridine invariably leads to the formation of the respective dimers [(R-ONO)MII(4,4’-bipy)MII(ONO-R)]. A similar compound having the bis(4-pyridyle)acetylene as spacer was formed upon cross-coupling Sonogashira reaction with ethynylpyridine chlorhydrate. The same cross-coupling reaction carried out between the electron releasing and electron withdrawing building blocks, respectively, allowed the preparation of the expected «push-pull» D-π-A system. The second-order NLO responses of compounds bearing a redox active methylenepyran ligand can be modulated upon reversible bi- (R = An) and tetra- (R = Fc) oxydation involving C-C bond formation/breaking reactions, thus forming a new class of NLO molecular switches
33
Leblond, Jérôme. "Synthèse et application catalytique de cyclodextrines modifiées Water-soluble phosphane-substituted cyclodextrin as an effective bifunctional additive in hydroformylation of higher olefins New water-soluble Schiff base ligands based on β-cyclodextrin for aqueous biphasic hydroformylation reaction." Thesis, Artois, 2018. http://www.theses.fr/2018ARTO0404.
Full textAbstract:
L'utilisation de cyclodextrines (CDs) comme additifs interfaciaux en catalyse biphasique aqueuse s'est avérée être une méthode efficace pour la transformation de composés hydrophobes. Pour améliorer de façon significative la proximité entre le catalyseur organométallique hydrosoluble et le composé organique à transformer, deux nouvelles familles de récepteurs moléculaires à base de CDs ont été développées. Une première stratégie a consisté à greffer de façon covalente une phosphine sulfonée sur une CD (système CD-P). Le récepteur moléculaire ainsi obtenu a permis d'améliorer significativement les performances catalytiques en hydroformylation d'alcènes hydrophobes. Une deuxième stratégie utilisant des dimères de CDs comportant un espaceur court et flexible s'est avérée moins concluante. En effet, la reconnaissance moléculaire simultanée du catalyseur et du substrat au sein des dimères de CDs n'a pu être démontrée, que ce soit en hydroformylation d'alcènes, en réaction de Heck ou en hydrogénation d'alcènesThe use of cyclodextrins (CDs) as interfacial additives in aqueous biphasic catalysis has proven to be an effective method for the transformation of hydrophobic compounds. To significantly improve the proximity between the water-soluble organometallic catalyst and the organic compound to be transformed, two new families of CD-based molecular receptors have been developed. A first strategy consisted in covalently grafting a sulfonated phosphine on a CD (CD-P system). The molecular receptor thus obtained significantly improved the catalytic performances in hydroformylation of hydrophobic alkenes. A second strategy using CD dimers with a short and flexible spacer proved less conclusive. Indeed, the simultaneous molecular recognition of the catalyst and the substrate within the CD dimer could not be demonstrated, whether in hydroformylation of alkenes, in Heck reaction or in hydrogenation of alkenes
34
Alzahrani, Nada Saleh. "The Synthesis and Characterization of the Bis-Substituted Phthalazine Using Bis-Substituted Isoindoline as Starting Material and Their Metals Complexes &The Synthesis and Charectrization of the Schiff Base Ligands with a Variety of Metals." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1408102563.
Full text
35
Sobola, Abdullahi Owolabi. "Synthesis, characterization and antimicrobial activity of copper (II) complexes of some hydroxybenzaldimines and their derivatives." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1016258.
Full textAbstract:
This study focuses on the antimicrobial activity of Cu(II) complexes of some orthohydroxybenzaldimines and its derivatives. Four different categories of Schiff base ligands were prepared by condensing salicylaldehyde, o-vanillin, p-vanillin and vanillin with p- and osubstituted anilines; 1-aminonaphthalene; 2- and 3-aminopyridine; 2- and 3- aminomethylpyridine as well as 2-aminobenzimidazole. The last category was prepared from ophenylenediamine and o-vanillin. The Schiff base ligands have been characterized by a combination of elemental analysis and spectral (¹H- and ¹³C-NMR, UV/Visible, infrared and Raman) data. The existence of strong intramolecular hydrogen bonding in the orthohydoxybenzaldimines was evident from the chemical shift values of the hydroxyl proton in the ¹H-NMR spectra of the Schiff base ligands. The hydroxyl proton resonates at high frequency and thus absorbed far downfield at 13.46-11.83 ppm, reflecting the presence of hydrogen bonding between the hydroxyl proton and the imine nitrogen. In the p-substituted aniline analogues of the Schiff base, a plot of the chemical shift values of the hydroxyl proton against the Hammett's substituent parameters gave a linear correlation between the electronegativities of the substituents and the chemical shift values. The nitro group with the highest electronegativity caused the least deshielding of the hydroxyl proton and thus absorbed upfield compared to the less electronegative substituents such as the CH3 and OCH3 analogues. Likewise, in the solid state infrared spectra of the ligands, the hydroxyl stretching band of the ortho-hydroxyl Schiff base ligands was observed as a very broad band and at much lower frequency, 3100-2100 cm⁻¹, indicating the existence of strong intramolecular hydrogen bonding. In the same vein, ¹H- and ¹³C-NMR spectral data for the Schiff base ligands indicated that the prepared compounds exist in the enol form in aprotic solvent, chloroform. The methine proton appeared as singlet and there was no carbonyl signal in the ¹³C-NMR spectra of the Schiff base ligands. This was supported by the infrared data having no vibrational band attributable to the carbonyl stretching of the keto-form of the Schiff base ligands in solid state. However, the UV/Visible study of the Schiff base ligands in protic solvent, methanol, suggested the existence of some of the Schiff base ligands in keto-enol form. A band at greater than 400 nm was observed in the UV/Visible spectra of the ligands and this has been attributed to the presence of the keto form of orthohydroxyl Schiff base ligands in solution. A plot of the molar absorptivity (ε) of the band at greater than 400 nm against Hammett substituent parameters revealed that the intensity of the bands increased with the electronegativity of the substituents. The Cu(II) complexes of salicylaldehyde, o-vanillin and a few p-vanillin based Schiff base ligands are reported in this work. It was observed that introduction of Cu(II) ions into the ligand system resulted in the hydrolysis of the imine band in few cases. All the isolated complexes have been characterized by elemental analysis, conductivity measurement, infrared and UV/Visible spectral data. The structures of three of the Cu(II) complexes were further confirmed by X-ray single crystal diffraction. The Schiff base ligands either coordinated as neutral base through the imine nitrogen or via the imine nitrogen and the phenolic oxygen atoms. In addition, the benzimidazole-based and ovan-2-pico analogues equally coordinated through the imidazole N-3 nitrogen and the azine nitrogen respectively; thus acted as tridentate. In general, the synthesized Cu(II) complexes fell into seven categories viz: [Cu(LH)Cl(H₂O)]Cl; [Cu(LH)₂Cl₂].xH₂O; [CuL₂]; [Cu₂L₂]; [Cu(LH)Cl(H₂O)]Cl; and [MLCl]. The Cu(II) complexes of the form, M(LH)₂Cl₂.xH₂O were either 1:1 or non-electrolyte in methanol and DMF. The third category, CuL₂, was however, non-electrolyte existing as neutral four coordinate Cu(II) complexes. X-ray single crystal structure of Cu(II) complexes derived from the ammonia-based Schiff bases revealed a square planar geometry for the complexes and this agreed with the planar geometry that has been reported for Cu(II) complexes of N-arylsalicylaldimines of the type studied in this work. The complexes, [Cu₂L₂], resulted from the ortho-hydroxyaniline analogues and were polymeric with the Schiff base ligands coordinating to the Cu(II) ions as tridentate dibasic via the imine nitrogen, phenolic oxygen and the aminophenolic oxygen atoms. Cu(II) complexes prepared from ovan-2-ampy and ovan-2-pico Schiff bases were of the forms [Cu(LH)Cl(H₂O)]Cl and [CuLCl] respectively. The X-ray crystal structure of [Cu(ovan-2- pico)Cl] revealed a four-coordinate square planar geometry for the complex. In the same vein, the o-phenylenediamine complexes were of the form [Cu(L)(H₂O)], with the X-ray crystal structure of [Cu(bis-ovanphen)(H₂O)] revealing a square pyramidal geometry. The Schiff base ligands and the isolated Cu(II) complexes have been evaluated for their antimicrobial activity against three bacterial strains (Escherichia coli ATCC® 8739™*, Staphylococcus aureus subsp. aureus ATCC® 6538™* and Bacillus subtilis subsp. spizizeni ATCC® 6633™*) and one fungal strain, Candida albicans ATCC® 2091™*, using agar disc diffusion and broth dilution techniques. It was observed that the presence of the methoxyl group at the ortho-position of the aldehyde moiety of the Schiff base ligands enhanced the activity of the ligand tremendously and thus the o-vanillin analogues showed the highest potency against the tested organisms. In addition, the hydroxyaniline analogues were equally the most promising of all the substituted aniline based Schiff bases. The o-vanillin analogues of the aminopyridines and aminomethylpyridines also exhibited significant activity against the tested organisms. All the 2-aminobenzimidazole series were active against the tested organisms. It should be noted that E. coli was the least susceptible of all the microorganisms while the highest potency was exhibited against the fungus of choice, Candida albicans. Lastly, chelation of the Schiff base ligands with Cu(II) ions did not have significant influence on the activity of the free ligands.
36
Black, Daniel. "Studies on binuclear Schiff-base compartmental ligand complexes." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363560.
Full text
37
周向葛 and Xiangge Zhou. "Asymmetric reactions catalyzed by transition metal complexes containing binaphthyl schiff bases and chiral porphyrinato ligands." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31239833.
Full text
38
Zhou, Xiangge. "Asymmetric reactions catalyzed by transition metal complexes containing binaphthyl schiff bases and chiral porphyrinato ligands /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21021363.
Full text
39
Al-Shihri, Ayed Saad Merzin. "Application of analytical methods in the co-ordination chemistry of some penta- and hexa-dentate ligands." Thesis, University of Essex, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257188.
Full text
40
Flores, Leonã da Silva. "Síntese, caracterização e estrutura cristalina de redes metalorgânicas com ligantes mistos N- e O- doadores." Universidade Federal de Juiz de Fora, 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/329.
Full textAbstract:
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-01-05T09:56:54Z
No. of bitstreams: 1
leonadasilvaflores.pdf: 7703560 bytes, checksum: 6e5f7330b9f5bb6e7d5e649e91d606e6 (MD5)Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T16:05:33Z (GMT) No. of bitstreams: 1 leonadasilvaflores.pdf: 7703560 bytes, checksum: 6e5f7330b9f5bb6e7d5e649e91d606e6 (MD5)
Made available in DSpace on 2016-01-25T16:05:33Z (GMT). No. of bitstreams: 1 leonadasilvaflores.pdf: 7703560 bytes, checksum: 6e5f7330b9f5bb6e7d5e649e91d606e6 (MD5) Previous issue date: 2015-08-21
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
O objetivo deste trabalho foi o de sintetizar MOFs com ligantes mistos, N- e O- doadores, utilizando alguns cátions metálicos da primeira série de transição como conectores de rede. Foram obtidas as redes de coordenação CoPDC2D e ZnPDC2D, que são isoestruturas as quais se estendem bi-dimensionalmente. Essas formam laços com 16-circuitos (circuitos mais curtos que contemplam 16 átomos), e incluem apenas o ligante 2,5-piridinodicarboxilato 2,5-pdc e os cátions (Co2+ e Zn2+) na coordenação. Algumas diferenças entre as sínteses aqui reportadas e aquelas publicadas são mostradas. Este trabalho também reporta brevemente o estudo topológico dessas redes bidimensionais. Todavia, foi obtida uma nova rede de coordenação ZnPDC1D, envolvendo a formação de laço (circuitos mais curtos de átomos), os quais se estendem unidimensionalmente, e envolvem os cátions Zn2+ e o ligante 2,5-pdc. Além disso, foi reportada uma série de novos complexos CuPDC0D, MnPDC0D, CuPDC0Dq e CuPDC0Dr, aniônicos, envolvendo apenas o ligante 2,5-pdc e os íons Cu2+ e Mn2+. Estes sistemas formam monômeros, MnPDC0D e CuPDC0Dr, ou dímeros oxo-metalatos, CuPDC0D e CuPDC0Dq, e contemplam cátions etilenodimina na rede cristalina, formando complexos metálicos (no caso do CuPDC0Dq. Finalmente, faz-se uma discussão sobre os ligantes nitrogenados 1,2-bis(2-piridil)etilenediamina 2-bpen e 1,2-bis(4-piridil)etilenediamina 4-bpen, que foram sintetizados, porém não foi observada a coordenação destes em nenhum dos sistemas aqui reportados. Tal fato foi atribuído à hidrólise dos ligantes nitrogenados (Bases de Schiff) e, portanto, foi proposto um mecanismo para essa hidrólise nos sistemas obtidos. A estrutura cristalina do ligante 2-bpen, ainda não reportada na literatura, foi discutida.
The aim of this work was the synthesis of MOFs with mixed ligands N- and O- donors from some metal cations of first series transition, as connectors of the net. In this work has been obtained coordination networks CoPDC2D and ZnPDC2D, that are iso-structures, which extend two-dimensionally forming loops with 16-shortest circuits, including the ligand 2,5-pyridinedicarboxylate 2,5-pdc and the Co2+ and Zn2+ cations, respectively. Both structures were recently published, however there some differences between the syntheses and the yield. Moreover, this work reports briefly the topological study of these two-dimensional networks. Additionally, were obtained a new coordination network ZnPDC1D, including loops formation, which extend one-dimensionally containing the cation Zn2+ and 2,5-pdc ligand. Here, were reported a series of new complexes CuPDC0D, MnPDC0D, CuPDC0Dq and CuPDC0Dr, anionic, including just the 2-5-pdc ligand and some this having Cu2+ e Mn2+ ions. This systems are monomers MnPDC0D and CuPDC0Dr or oxometalates dimmers CuPDC0D and CuPDC0Dq, including etilenodiamine on the crystalline network and, in some cases, participating on coordination CoPDC0Dq. Finally, are discussed about the nitrogenous ligands 1,2-bis(2-pyridil)etilenediamine 2-bpen and 1,2-bis(4-pyridil)etilenediamine 4-bpen, that were synthesized and characterized but not was observed the coordination in any system here reported. This has been attributed to the hydrolysis of nitrogenous ligands and, therefore, was proposed a mechanism for hydrolysis of these systems. The crystal structure of ligand 2-bpen, not yet reported in literature, was discussed.
41
Gichinga, Moses G. Striegler Susanne. "Synthesis, spectroscopic investigation and immobilization of copper(II) complexes as oxidation catalysts." Auburn, Ala, 2009. http://hdl.handle.net/10415/1857.
Full text
42
Magwa, Nomampondo Penelope. "A spectroscopic study of the electronic effects on copper (II) and copper (I) complexes of ligands derived from various substituted benzyaldehyde- and cinnamaldehyde- based schiff bases." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1006712.
Full textAbstract:
Several Schiff base ligands, N, N‟-(aryl)benzyaldiimine ligands (R-BEN); N, N‟-(aryl)benzyaldiamine dihydrochloride ligands (R-BENH•2HCl); N, N‟-(aryl)benzyaldiamine ligands (R-BENH); N, N‟-bis(cinnamaldiimine) ligands (R-CA2EN) were synthesized for the investigation of the electronic effect of the substituents at para-position of the Schiff base ligands and their copper complexes. The synthesis of Schiff bases was carried out by reacting a series of para-substituted benzyaldehyde, and para-substituted cinnamaldehyde with ethylenediamine. The imine group of Schiff bases, N, N‟-(aryl)benzyaldiimine ligands and N, N‟-bis(cinnamaldiimine)ligands were reduced to corresponding amines with sodium borohydride in methanol These ligands, N, N‟-(aryl)benzyaldiamine ligands (H-BENH), N, N‟-bis(cinnamaldiimine)ligands (CA2EN) were reacted with copper(II) dihalide and copper(I) monohalide ions respectively to form complexes. The ligands and their complexes were analysed using elemental analyses, FT-IR spectroscopy (mid-IR), UV/vis in aprotic and protic solvents,while mass spectrometry, 1H-NMR and 13C-NMR were used to further analyse the ligands. By using substituent parameters, both the single and dual substituent parameters with the spectroscopic data obtained from the spectroscopic techiques mentioned above, it was hoped to monitor and determine whether the electronic effects (resonance or inductive effcets) was predominantly within the Schiff base ligands and copper complexes. The NMR studies with dual substituent parameters suggest that the effects of the substituents are transimitted through the ligands, via resonance effects and that the phenyl group is nonplanar with the azomethine in N, N‟-(aryl)benzyaldiimine ligands. The presence of an extra double bond in Schiff base {(N, N‟-bis(cinnamaldiimine) ligand)} altered the electron density. The UV/vis studies showed that the symmetry of the N, N‟-bis(4-R-benzyl)-1, 2-diaminoethanedihalidecopper(II) complexes were predominantly tetrahedral for both chloro and bromo complexes. The correlation studies from mid-infrared were beneficial in monitoring the effect experienced by N, N‟-(aryl)benzaldiimine ligands, the studies suggest that the inductive effect is more pronounced at the C=N.
43
Soulet, Frédéric. "Electrodes greffées par des complexes de coordination du fer à ligands bases de Schiff du type Salen." Toulouse 3, 1996. http://www.theses.fr/1996TOU30036.
Full textAbstract:
Les annees 1980 ont ete marquees par l'apparition de nouveaux materiaux: les polymeres organiques conducteurs comme les polyanilines, les polypyrroles et les polythiophenes qui sont synthetises par oxydation electrochimique. Un nouveau developpement de ces materiaux est apparu avec l'idee d'introduire dans la matrice des especes possedant une activite electrochimique propre, comme des complexes de coordination. Ces materiaux dopes constituent les electrodes modifiees qui sont utilisees en electrocatalyse. Les complexes de coordination retenus pour cette etude sont essentiellement des complexes du fer a ligands du type bases de schiff. Les electrodes modifiees sont obtenues par electropolymerisation de derives thiopheniques et pyrroliques greffes. Afin de s'assurer que le greffage du complexe ne modifie en rien leurs proprietes, une etude comparative en solution de plusieurs complexes de fer bases de schiff a ete realisee et a permis de mettre en evidence leur tres grande reactivite vis-a-vis du dioxygene. Le greffage de complexes de coordination modifie sensiblement les conditions d'electropolymerisation. En effet, de facon a obtenir des films de polymeres resistants nous avons eu recours a la copolymerisation. L'etude du comportement de telles electrodes par rapport aux electrodes metalliques classiques a ete realisee par caracterisation electrochimique de systemes electrochimiques connus (le ferrocene et le fesalencl). Ces etudes revelent que de telles electrodes possedent des domaines d'electroactivite restreints mais se comportent dans ce domaine la comme les electrodes metalliques classiques et possedent les proprietes chimiques des especes dopantes. Ce type d'electrodes peut trouver des applications dans differents domaines (autres que l'electrocatalyse) notamment dans l'elaboration de capteurs de metaux
44
Bahron, H. "Characterization of new metal complexes of Schiff bases and macrocyclic ligands and some mononitrosyl derivatives." Thesis, University of Surrey, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240159.
Full text
45
Chaves, Henrique Koch. "Complexos derivados do fragmento fac-[M(CO)3L] (M = Re e Tc) com ligantes multidentados como novos agentes para radioterapia e radiodiagnóstico." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-20092016-153312/.
Full textAbstract:
Esta tese apresenta a síntese e a caracterização de novos complexos de rênio e tecnécio utilizando como agentes complexantes ligantes assimétricos do tipo base de Schiff e ligantes triaminas derivadas da dietilenotriamina. Os ligantes assimétricos foram sintetizados através de reações de condensação entre 2,2\'-dihidroxibenzofenona e as aminas alifáticas etilenodiamina e dietilenotriamina, formando, respectivamente, os ligantes 2,2\'-(((2-aminoetill)imino)metileno)difenol(HL1) e 2,2\'-(((2-((2-aminoetil)amino)etil)imino) metileno)difenol (HL2). Os ligantes simétricos foram sintetizados através de reações de condensação entre benzaldeído, 4-hidroxibenzofenona e 3- e 4-metoxibenzaldeído com a amina alifática dietilenotriamina, formando, respectivamente, os ligantes simétricos tridentados tricloridrato de N1-benzil-N2-(2-(benzilamino)etil)etano-1,2-diamina (HL3), 4,4\'-(((azanodiilbis(etano-2,1-diil))bis- (azanediil))bis(phenilmetileno))difenol (HL4), tricloridrato de N1-(4-metoxibenzil)-N2-(2-((4-metoxibenzil)amino)etil) etano-1,2-diamina (HL5) e tricloridrato de N1-(3-metoxibenzil)-N2-(2-((3-metoxibenzil)amino)etil)etano-1,2-diamina (HL6). Reações de complexação foram conduzidas com os precursores metálicos de ReI eTcI. O complexo [Re(CO)5Br] foi utilizado como precursor de ReI. Foi obtido o complexo neutro do tipo fac-[Re(CO)3(L1)] e complexos catiônicos do tipo fac-[Re(CO)3(HL2,3,4,5,6)]Br. Os ligantes e complexos foram caracterizados por ponto de fusão, análise elementar (CHN), espectroscopia de absorção na região do infravermelho, espectroscopia de absorção na região do ultravioleta visível, espectroscopia de ressonância magnética nuclear de 1H e 13C, espectrometria de massas (MS-ESI) e, no caso dos complexos com os ligantes HL1,2,5,6, difração de raios X pelo método do monocristal. Foi realizada a marcação do ligante HL3 com o complexo fac-[[99mTc](H2O)(CO)3]+, formando o complexo fac-[[99mTc](CO)3(HL3)]Br e outras espécies em solução, que foram separadas por HPLC. Adicionalmente, realizou-se um estudo comparativo entre o método convencional de síntese (aquecimento) com o método de síntese no qual microondas são utilizadas. O complexo de tecnécio foi caracterizado por HPLC e eletroforese em papel. Foram realizados testes de estabilidade em cisteína, histidina e tampão PBS. Os testes de estabilidade mostraram que o complexo apresenta boa estabilidade por período de 3 horas. Foi determinado o coeficiente de partição desse complexo, tendo sido observado o caráter lipofílico do mesmo. Foram também realizados testes biológicos in vitro de captação e extrusão com células B16F10 (melanoma murino), onde as células captaram o complexo fac-[[99mTc](CO)3(HL3)]Br,em torno de 4,2%, e mantiveram retidas em seu interior cerca de 20% do complexo, após 60 minutos de incubação. O teste de viabilidade celular por azul de Tripan, mostrou estabilidade das células, durante os experimentos de captação e extrusão, frente às espécies radioativas, apresentando uma viabilidade celular superior a 90% em todos os casos.This thesis presents the synthesis and characterization of novel rhenium and technetium complexes using as complexing agents asymmetric ligands (Schiff\'s bases type ligands) and triamines ligands derived from diethylenetriamine. The asymmetric ligands were synthesized by condensation reactions between 2,2\'-dihydroxybenzophenone and the aliphatic amines ethylenediamine and diethylenetriamine, giving rise, respectively, to the ligands 2,2\'-(((2-aminoetill)imino) methylene)diphenol (HL1) and 2,2\'-(((2-((2-aminoethyl)amino)ethyl)imino) methylene) diphenol (HL2). The symmetrical ligands were synthesized by condensation reactions between benzaldehyde, 4-hydroxybenzophenone and 3- and 4-methoxybenzaldehyde with the aliphatic amine diethylenetriamine, resulting in the formation, respectively, of the symmetrical tridentated ligands trihydrochloride N1-benzyl-N2-(2-(benzylamino)ethyl)ethane-1,2-diamine (HL3), 4,4\'-(((azanodiilbis(ethane-2,1-diyl))bis(azanediil))bis(phenilmetileno))diphenol (HL4), trihydrochloride N1-(4-methoxybenzyl)-N2-(2-((4-methoxybenzyl)amino)ethyl)ethane-1,2-diamine (HL5) and trihydrochloride N1-(3-methoxybenzyl)-N2-(2-((3-methoxybenzyl)amino)ethyl)ethane-1,2-diamine (HL6). Complexation reactions were carried out using ReI and TcI as metal precursors. The complex [Re(CO)5Br] was used as ReI precursor. Neutral complexe of the type fac-[Re(CO)3(L1)] and cationic complexes of the type fac-[Re(CO)3(HL2,3,4,5,6)]Br were obtained. The ligands and complexes were characterized by melting point, elemental analysis (CHN), infrared absorption spectroscopy, UV-visible absorption spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry (MS-ESI) and for the complexes with the ligands HL1,2,5,6, single crystal X ray diffraction method. Labeling studies were carried out for the HL3 ligand with the complex fac-[[99mTc](H2O)(CO)3]+, forming the complex fac-[[99mTc](CO)3(HL3)]Br and other species in solution, which were separated by high performance liquid chromatography (HPLC). Additionally, a comparative study was done between the conventional (heating) and the synthesis method using microwaves. The technetium complex was characterized by HPLC and electrophoresis on paper. Stability tests were conducted on cysteine, histidine and PBS buffer. The stability tests showed that the compound presents good stability over a 3 hour period. The lipophilic character of the complex was confirmed by the determination of the partition coefficient. In addition, In vitro biolgical tests of captation and influx were performed on B16F10 cells (murine melanoma). The cells captured around 4.2% of the complex fac-[[99mTc](CO)3(HL3)]Br and retained 20% of the amount inside after 60 minutes of incubation. The Trypan blue exclusion test of cell viability showed stability of the cells during the influx and captation experiments, front of the radioactive species, showing cell viability greater than 90% in all cases.
46
XAVIER, Tatiana Teodoro. "Síntese, caracterização e avaliação da atividade anti-leishmania de complexos de Paládio(II) contendo ligantes imínicos." Universidade Federal de Alfenas, 2016. https://bdtd.unifal-mg.edu.br:8443/handle/tede/890.
Full textAbstract:
Nas últimas décadas, os complexos de metais de transição vêm sendo investigados devido as suas atividades antineoplásica e tripanossomicida. Há diversos trabalhos na literatura que buscam explorar as propriedades de complexos de paládio, entre elas podemos citar: avaliação de atividade como anti-proliferativo de células cancerosas, avaliação de atividade anti-inflamátoria, avaliação de atividade bactericida e aplicações em processos catalíticos. Nosso material de estudo foram compostos de paládio(II) contendo ligantes imínicos. Os Ligantes N,N’-bis(3,4-dimetoxibenzaldeído)etano-1,2-diamina (3,4dm-1,2am) e N-(p-dimetilamino)benzilideno-(p-dimetilamino)anilina (4dm-1,4fen) são bases de Shiff já relatadas na literatura. Os compostos foram caracterizados por análise elementar, análise termogravimétrica, espectroscopia de ressonância magnética nuclear (RMN) de ¹H e ¹³C, espectroscopia de ultravioleta-visível (UV-Vis) e de infravermelho (IV). Os resultados de RMN sugerem a formação de complexos N,N-quelato ([Pd(Cl)2(3,4dm-1,2am)], [PdBrCl(3,4dm-1,2am)], [Pd(N3)2(3,4dm-1,2am)], [Pd(NCO)2(3,4dm-1,2am)]). As espectroscopias vibracionais e na região do ultravioleta-visível mostraram o deslocamento das bandas de absorção dos complexos indicando a coordenação do ligante, bem como a substituição regioespecífica dos cloretos. Esta técnica confirmou que os grupos azida e cianato estão coordenados preferencialmente de modo N-terminal. A análise dos espectros de RMN de ¹H e ¹³C, UV-Vis e IV do ligante nitrogenado (4dm-1,4fen) e do complexo ciclopaladado ([Pd(μ-Cl)(4dm-1,4fen)]2) mostrou a presença de sinais compatíveis com as estruturas propostas. As curvas TG/DTA mostraram que a termodecomposição dos complexos de paládio(II) ocorreram em etapas que envolvem a eliminação dos ligantes orgânicos e inorgânicos, e etapas de oxidação do paládio formando óxido de paládio e em seguida a redução de óxido de paládio em paládio(0), sendo este o constituinte da massa residual observada ao final das curvas TG, as quais possuem valores concordantes com os valores esperados. Empregou-se estes compostos em ensaios biológicos frente à Leishmania, onde foram realizados experimentos in vitro de células promastigotas L. amazonensis onde os compostos [Pd(N3)2(3,4dm-1,2am)] e [Pd(μ-Cl)(4dm-1,4fen)]2 apresentaram IC50 próximo ao da Anfotericina B.For some time, transition metal complexes, especially cisplatin, have been investigated due to their antineoplastic and trypanocidal activities. There are several studies in literature that seek to exploit the properties of palladium complexes, such as cancer cells anti-proliferative activity, anti-inflammatory activity, bactericidal activity and applications in catalytic processes. As a study material, we have palladium(II) compounds, containing iminic ligands. The N,N'-bis(3,4-dimethoxybenzaldehyde)ethane-1,2-diamine (3,4dm-1,2am) and N-(p-dimethylamino)benzylidine-(p-dimethylamino)aniline ( 4dm-1,4fen) ligand is a Schiff Base and has its synthesis and characterization reported in literature. The compounds were characterized by elemental and thermogravimetric analyses, as well as nuclear magnetic resonance spectroscopies ¹H and ¹³C, ultravioleta-visible and infrared (IR) spectroscopies. The results of NMR indicate the formation of N,N-chelated products ([Pd(Cl)2(3,4dm-1,2am)], [PdBrCl(3,4dm-1,2am)], [Pd(N3)2(3,4dm-1,2am)], [Pd(NCO)2(3,4dm-1,2am)]). Regarding the vibrational spectroscopy in the ultraviolet -visible, there was the shift of the absorption bands of the complexes indicating coordination of the ligand and the substitution of groups chlorides. This technique confirmed that the azide and cyanate groups are preferably coordinated N-terminal. The analysis of NMR ¹H and ¹³C, UV-Vis and IR spectra of ligand nitrogen (4dm-1,4fen) and complexes cyclopalladated ([Pd(μ-Cl)(4dm-1,4fen)]2) showed the presence of signs consistent with the proposed. The TG/DTA curves showed that the thermal decomposition of the palladium(II) complexes occurred in steps that involve the removal of both inorganic and organic ligand, and palladium oxidation steps forming palladium oxide followed by the reduction of palladium oxide into palladium(0), this being the constituent of the residual mass observed at the end of the TG curves, which have values consistent with the expected ones. The synthesized compounds were tested in biological assays against Leishmania where in vitro experiments with L. amazonensis promastigote cells were performed, and the compounds [Pd(N3)2(3,4dm-1,2am)] and [Pd(μ-Cl)(4dm-1,4fen)]2 showed IC50 near the Amphotericin B.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
47
Magee, Chad Leroy Keller S. W. "The synthesis and characterization of 1,1'-disubstituted ferrocene imine Schiff base ligand systems for use as potential environmental heavy metal cationic sensors." Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/7117.
Full textAbstract:
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb. 23, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dr. Steven W. Keller, Dissertation Supervisor. Vita. Includes bibliographical references.
48
MENEZES, Thaís Meira. "Estudo experimental e teórico das interações entre derivados de bases de Schiff e marcadores proteicos de neoplasias." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/25435.
Full textAbstract:
Submitted by Fernanda Rodrigues de Lima (fernanda.rlima@ufpe.br) on 2018-08-02T20:58:21Z
No. of bitstreams: 2
license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5)
DISSERTAÇÃO Thaís Meira Menezes.pdf: 5590290 bytes, checksum: 6516515f3f28c707bbffd79ee5b3e400 (MD5)Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-08-07T19:25:58Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Thaís Meira Menezes.pdf: 5590290 bytes, checksum: 6516515f3f28c707bbffd79ee5b3e400 (MD5)
Made available in DSpace on 2018-08-07T19:25:58Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Thaís Meira Menezes.pdf: 5590290 bytes, checksum: 6516515f3f28c707bbffd79ee5b3e400 (MD5) Previous issue date: 2017-03-15
CNPq
Para o desenho de drogas com maior compatibilidade com o sítio de ligação é extremamente importante ter conhecimento do alvo molecular a que se destina o fármaco e da sua maneira de interação, ou seja, é preciso estudar a região onde será feita a conexão com o ligante e o mecanismo da reação. A ampla gama de aplicações para compostos orgânicos derivados de base de Schiff na industria química estende-se desde catalisadores, estabilizadores, intermediário de síntese e corantes. No contexto biológico, estes compostos tem sido empregado devido as suas atividade contra bacterias, fungos, virus, inflamação e neoplasias. Esta classe de moléculas apresentam relevante flexibilidade sintética e apresentam alta seletividade e sensibilidade em relação ao átomo de uma metaloenzima. Diante da relevância destes compostos no contexto biológico foram sintetizados e caracterizados nessa dissertação alguns derivados de base de Schiff. Visando estudar a biodisponibilidade do ponto de vista farmacocinético, estes compostos foram sujeitos a estudos de interação com a proteína BSA, através do mapeamento e monitoramento das mudanças das linhas de RMN frente a titulação com a proteína e os constantes de ligação Kd foram determinadas. Os compostos obtidos foram sujeito a estudos de interação teorico-experimental com a proteína tirosinase que esta envolvida com a mela-nogênese e um marcador neoplásico altamente relevante. A partir do estudo realizado, infere-se que os compostos devidamente sintetizados e caracterizados apresentaram moderada interação com a BSA, forte interação com íons cobre, indicando uma possível coordenação dos compostos com o metal, além da forte interação da NW-F e AMTAC 02 com a enzima tirosinase. Finalmente estudos de inibição de atividade enzimatica foram conduzidos com o composto acridínico AMTAC01 e os resultados mostraram que este composto inibe a proteína com valores de dose resposta IC50 de 8,8.10−8, mesma ordem de grandeza que o inibidor comercial ácido kójico, o que qualifica o composto AM-TAC01 como um potente inibidor da enzima tirosinase.
For the design of drugs with greater compatibility with the binding site, it is extremely important to the molecular target for which the drug is intended and its mode of interaction, that is, it is necessary to study the region where the connection with the ligand and the mechanism of the dog. The wide range of applications for organic compounds derived from Schiff base in the chemistry ranges from catalysts, stabilizers, synthesis intermediates and colorants. At the biological context, these compounds have been employed due to their activity against bacteria, fungi, viruses, inflammation and neoplasms. This class of molecules presents significant flexibility synthetic and have high selectivity and sensitivity to the atom of a metalloenzyme. In view of the relevance of these compounds in the biological context were synthesized and characterized in this dissertation some Schiff base derivatives. Aiming to study the bioavailability of the from a pharmacokinetic perspective, these compounds were subjected to interaction studies with the BSA protein, through the mapping and monitoring of the changes of the NMR lines against titration with the protein and the Kd binding constants were determined. The obtained compounds were subjected to studies of the theoretical-experimental in-teraction with the protein tyrosinase that is involved with the melanogenesis and a highly relevant neoplastic marker. Based on the study, it is inferred that The duly synthesized and characterized compounds presented moderate interaction with BSA, strong interaction with copper ions, indicating a possible coordination of the compounds with the As well as the strong interaction of NW-F and AMTAC 02 with the enzyme tyrosinase. Finally, studies of Inhibition of enzyme activity were conducted with the acridine compound AMTAC01 and the results showed that this compound inhibits the protein with IC 50 dose response values of 8.8.10-8, same order of magnitude as the kojic acid commercial inhibitor, which qualifies the compound AMTAC 01 as a potent inhibitor of the enzyme tyrosinase.
49
Tamgho, Ingrid-Suzy. "Synthesis of Ligands and Macrocycles Based on 1,3-Diiminoisoindoline and Study of New Highly Fluorescent and Symmetric Pyrrole-BF2 Chromophores." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1412163224.
Full text
50
Sabino, Gustavo Levendoski. "Investigação da reatividade de complexos metálicos com ligantes bases de Schiff frente a infecções parasitárias." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-21012015-085103/.
Full textAbstract:
Ligantes oxindolimínicos foram sintetizados através de procedimentos já desenvolvidos em nosso laboratório, a partir do 2,3-dioxindol (isatina) e aminas ou diaminas selecionadas, e em seguida metalados. Foram investigados dois complexos de cobre(II) com os ligantes isaepy, preparado a partir de 2-(2-aminoetilpiridina) e isapn, a partir de 1,2-diaminoetano, e os correspondentes complexos de zinco(II). Após caracterização por diversas técnicas, sua reatividade com relação a biomoléculas (HSA e DNA) foi verificada, através de medidas de fluorescência e dicroísmo circular. Posteriormente, sua reatividade antiparasitária frente a T. cruzi foi testada. Todos eles apresentaram atividade tóxica frente às formas tripomastigota e amastigota do parasita, com índices de seletividade bastante promissores, quando comparados à droga atualmente em uso (benzonidazol) e outras alternativas descritas na literatura. Anteriormente estes complexos já haviam demonstrado atividade pró-apoptótica frente a diversas células tumorais, baseado em sua capacidade de gerar espécies reativas (EROs) e de inibir proteínas específicas, como a topoisomerase humana IB. Os resultados aqui obtidos deram origem a um pedido de patente (BR10 2013 026558-6, depositado junto ao INPI em 15/outubro/2013) visando o possível desenvolvimento de novos fármacos para a doença de Chagas.Oxindolimine ligands were synthesized by procedures previously developed in our laboratory, from 2,3-dioxoindole(isatin) and amines or selected diamines, by condensation reactions, followed by metallation. Two copper(II) complexes with isaepy and isapn ligands, prepared from 2-(2-aminoethylpiridine) and 1,2-diaminoethane respectively, and their corresponding complexes of zinc(II) were investigated. After characterization by various techniques, their reactivity with respect to biomolecules (HSA and DNA) was verified, through measurements of fluorescence and circular dichroism. Subsequently, their antiparasitary reactivity against T. cruzi was tested. All complexes tested presents toxic activity against trypomastigote and amastigote forms of the parasite, with promising selectivity index, compared to drugs currently in use (benznidazole) and other alternative compounds described in literature. Previously, these complexes had shown pro-apoptotic activity against several tumor cells, based on their ability to generate reactive species and inhibit specific proteins, such as topoisomerases. The results obtained here gave rise to a patent application (BR10 2013 026558-6, deposited on INPI in October 15th, 2013), looking for a possible development of new drugs for Chagas disease.