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Doerrer, Linda H. (Linda Helen) 1968. "Cobalt, zinc, and cadminum tropocoronand complexes." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43296.
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Tirel, Emmanuel. "Zinc complexes for phosphate diester hydrolysis." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/7788/.
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This work focuses on catalysing the hydrolysis of DNA-like substrate with mononuclear zinc complexes. Particular attention is given to find new ways of activating the nucleophile of the reaction and to study the impact of organic groups that affect the microenvironment of the metal ion.
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Moreton, A. D. "Structure and reactivity of some aqueous zinc complexes." Thesis, University of Kent, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375179.
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Gianopoulos, Christopher G. "Development of Bulky Dipyrromethene Complexes of Aluminum, Zinc, and Rhodium." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418317025.
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Pratt, Jo-Anne Margaret. "The development of zinc (II) selective fluorescent ligands /." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09php915.pdf.
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Elrod-Erickson, Monica (Monica Ann) 1969. "Structural and biochemical studies of zinc finger-DNA complexes." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/49650.
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Ritch, Grayson D. "Synthesis, Characterization, and Reactivity of Novel Zinc Coordination Complexes." Kent State University Honors College / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1399675758.
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Dollberg, Christopher Lawrence. "Zinc and ruthenium quinone diimine complexes synthesis and photophysical properties /." Columbus, Ohio Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1071171484.
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Thesis (Ph. D.)--Ohio State University, 2003.<br>Title from first page of PDF file. Document formatted into pages; contains xvii, 171 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Claudia Turro, Dept.of Chemistry. Includes bibliographical references (p. 168-171).
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Tabone, Roberta. "Sinthesys of heteroleptic zinc complexes for imaging in living cells." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19188/.
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This thesis arose from an interest in luminescence heteroleptic bis(dipyrrinato) Zn (II) complexes and their application in cell imaging, due to their attractive and fascinating characteristics. Among imaging technologies, near-infrared fluorescence imaging has been dedicated immense attention owing to its low absorption and autofluorescence from surrounding organism and tissues in this specific spectral region, which minimize background interference and improve tissue depth penetration. An ideal near-infrared probe should be equipped with excellence chemical and photophysical properties. The target of this work is the synthesis of new heteroleptic bis(dipyrrinato) Zn (II) complexes having two main features: the emission in the near-infrared region and water-solubility. In order to purse these intentions, the low-energy emission was achieved by expansion of π-conjugation of simple dipyrrins using Knoevenagel condensation106 and tri(ethylene)glycol chain was introduced to increase the water solubility of the final complex. Photophysical and luminescent properties of the new complexes were investigated. Finally, with a view to a potential biological use of these new complexes in biological environments, their biocompatibility was tested using a cell viability assay: (3-(4,5-dimethylthiazol-2-yl)-2’-5’-diphenyltetrazolium bromide (MTT) assay.
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Yang, Wen Yu. "Luminescent zinc and lanthanide complexes based on 2,2 '-dipyridylamine derivatives." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0020/MQ52968.pdf.
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Coleman, A. P. "Spectroscopic aspects of alkyl complexes of zinc cadmium and mercury." Thesis, University of East Anglia, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254672.
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Kozhukh, Julia 1985. "Nitric oxide reactions of bio-Inspired zinc and cobalt complexes." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73360.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2012.<br>Vita. Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>Chapter 1. Bioinorganic Chemistry of Nitric Oxide and of Some of Its Targets The redox-active nature of nitric oxide (NO) regulates the chemistry and roles of NO in biology. The interactions of NO with nitric oxide synthases, metallothioneins, and cobalamin-containing enzymes are discussed. Bioinspired small molecule models for metalloprotein active sites are introduced, and the ability of ligands to control the steric and electronic properties of coordinated metal centers is demonstrated. The bioinorganic chemistry of NO and its targets is described in the context of the investigations presented in this thesis. Chapter 2. Zinc Thiolate Reactivity toward Nitrogen Oxides: Insights into the Interaction of Zn2+ with S-Nitrosothiols and Implications for Nitric Oxide Synthase Zinc thiolate complexes containing N2S tridendate ligands were prepared to investigate their reactivity toward reactive nitrogen species. This type of chemistry is proposed to occur at the zinc tetracysteine thiolate site of nitric oxide synthase (NOS). The complexes are unreactive toward nitric oxide in the absence of dioxygen, strongly indicating that NO cannot be the species directly responsible for S-nitrosothiol formation and loss of Zn2* at the NOS dimer interface in vivo. S-Nitrosothiol formation does occur upon exposure of zinc thiolate solutions to NO in the presence of air, however, or to NO2 or NOBF4, indicating that these reactive nitrogen/oxygen species are capable of generating the S-nitrosothiol. Interaction between simple Zn2+ salts and pre-formed S-nitrosothiols leads to decomposition of the -SNO moiety, resulting in release of gaseous NO and N20. The potential biological relevance of this chemistry is discussed. Chapter 3. Reactions of Organozinc Thiolates with Nitrosonium Ion: C-Nitroso Formation by Intramolecular Transnitrosation The organometallic species [ZnPAThEt] and [ZnPAThMes] are prepared, and their reactions with NOBF4 are characterized. The formation of C-nitrosoethane and C-nitrosomesitylene is confirmed, and structural characterization of C-nitrosomesitylene conclusively establishes the dimeric nature of the molecule in the solid state. An intramolecular transnitrosation reaction pathway for C-nitroso formation is proposed based on theoretical calculations. Chapter 4. Influence of Ligand Constraints on the Reactivity of Co(II) Complexes of Tetraazamacrocyclic Tropocoronand Ligands with Nitric Oxide Previous work on the reactivity of cobalt(II) complexes of tetraazamacrocyclic tropocoronand ligands with nitric oxide (NO) was extended to include the [Co(TC-5,5)] and [Co(TC-6,6)] derivatives. The cobalt mononitrosyl [Co(NO)(TC-5,5)] is isolated and structurally characterized from the reaction of [Co(TC-5,5)] and NO (g). In contrast, a {Co(NO) 2}'0 species is observed when [Co(TC-6,6)] is exposed to NO (g) and the nitrite complex [Co(NO2)(TC-6,6)] is structurally and spectroscopically characterized from reaction mixtures. The di(cobalt dinitrosyl) [Co2(NO) 4(TC-6,6)] is independently synthesized for spectroscopic comparison with reaction mixtures. This Chapter describes the first characterization of the dependence of cobalt(II) tropocoronand reactivity on linker chain length..<br>(cont.) Chapter 5. Reactivity of Tropocoronand-Bound Cobalt(III) Nitrite with Nitric Oxide as a Function of Polymethylene Linker Chain Length The studies on the dependence of cobalt(II) tropocoronand reactivity with nitric oxide (NO) on linker chain length, described in Chapter 4, were expanded to include the chemistry of the cobalt(III) nitrites [Co(NO2)(TC-n,n)] (n = 4 - 6) with NO. Complete conversion from the cobalt(III) nitrite to the cobalt mononitrosyl [Co(NO)(TC-4,4)] is demonstrated upon exposure to NO (g). In contrast, exposure of [Co(N0 2)(TC-5,5)] and [Co(N0 2)(TC-6,6)] to NO (g) results in conversion to a cobalt dinitrosyl adduct. This Chapter aims to broaden the field of cobalt(III) chemistry with NO. Chapter 6. Nitric Oxide Reactivity of Cobalt(III) Triflate and Cobalt(III) Thiolate Tropocoronand Complexes The reactivity of two cobalt(III) tropocoronands with NO (g) is described. [Co(TC-4,4)](OTf) undergoes reductive nitrosylation in the presence of NO (g), forming [Co(NO)(TC-4,4)], N20, and additional reactive species. The reaction releases one equivalent of protons for every equivalent of [Co(TC-4,4)](OTf) consumed. [Co(SC 6F5)(TC-4,4)] forms [Co(NO)(TC-4,4)] and the disulfide F5C6SSC6F5 in the presence of NO (g). We hypothesize that disulfide formation is followed by electrophilic aromatic substitution of F5C6S* onto the tropocoronand aromatic ring. Efforts to prepare substituted tropocoronand ligands and test the electrophilic aromatic substitution hypothesis are described. Chapter 7. Synthesis and Characterization of Mononuclear, Pseudotetrahedral Cobalt(III) Compounds The synthesis and characterization of two mononuclear cobalt(III) tropocoronand complexes, [Co(TC-5,5)](BF 4) and [Co(TC-6,6)](BPh 4), are reported. The cobalt(III) centers exist in rare pseudotetrahedral conformations, with twist angles of 650 and 740 for the [Co(TC-5,5]* and [Co(TC-6,6)]* species, respectively. Structural and electrochemical characteristics are compared with those of newly synthesized [Ga(TC-5,5)](GaCl4) and [Ga(TC-6,6)](GaCl 4) analogs.<br>by Julia Kozhukh.<br>Ph.D.
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Dollberg, Christopher L. "Zinc and ruthenium quinone diimine complexes: synthesis and photophysical properties." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1071171484.
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Sampson, Claire Louise. "Construction of dinuclear complexes using multidentate ligands." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311744.
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Ngan, Tung-wan. "Design, synthesis and studies of novel photochromic zinc(II) thiolate complexes." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31367380.
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Ngan, Tung-wan, and 顏冬芸. "Design, synthesis and studies of novel photochromic zinc(II) thiolate complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31367380.
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Tsotsoros, Samantha. "Platinum Complexes and Zinc Finger Proteins: From Target Recognition to Fixation." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/610.
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Bioinorganic chemistry strives to understand the roles of metals in biological systems, whether in the form of naturally occurring or addition of non-essential metals to natural systems. Metal ions play vital roles in many cellular functions such as gene expression/regulation and DNA transcription and repair. The study of metal-protein-DNA/RNA interactions has been relatively unexplored. It is important to understand the role of metalloprotein interactions with DNA/RNA as this enhanced knowledge may lead to better understanding of diseases and therefore more effective treatments. A major milestone in the development of this field was the discovery of the cytotoxic properties of cisplatin in 1965 and its FDA approval in 1978. Since then, two other chemotherapeutic drugs containing platinum, carboplatin and oxaliplatin, have been used in the clinic. These three compounds are all bifunctional with the ligands surrounding platinum In the cis conformation and rearrangement of the ligands to the trans orientation results in a loss of cytotoxic properties due to rapid deactivation through binding to S-containing proteins. This enhanced reactivity yields new opportunities to study the reactions between proteins and DNA. One of the first crosslinking experiments used transplatin to crosslink NCp7 to viral RNA in order to understand how/where the protein bound to RNA. We have studied the interaction between cis and trans dinuclear platinum complexes and the C-terminal zinc finger (ZF). The trans complex reacts at a faster rate than the cis isomer and causes N- terminal specific cleavage of the ZF. The dinuclear structure plays a critical role in the peptide cleavage as studies with transplatin (the mononuclear derivative) does not result in cleavage. Monofunctional trans platinum-nucleobase complexes (MPNs) serve as a model for the binding of transplatin to DNA. This provides an interesting opportunity to study their reactions with S-containing proteins, such as HIV1 NCp7. MPNs have been shown to bind to the C-terminal ZF of HIV1 NCp7, resulting in zinc ejection. This occurs through a two-step process where the nucleobase π-stacks with Trp37 on the ZF, followed by covalent binding at the labile Cl site to Cys. MPNs have also shown antiviral activity in vitro. The labile Cl on MPNs reduces specificity of these compounds, as it leaves an available coordination site on the platinum center for binding to other S-proteins or DNA. Therefore, we have moved to an inert PtN4 coordination sphere, [Pt(dien)L]2+ (dien= diethylenetri- amine). Due to the strong bond between platinum and nitrogen, covalent reactions are highly unlikely to occur at rapid rates. The strength of the pi-stacking interaction between nucleobases (free and platinated) and the aromatic amino acid, tryptophan (Trp), showed an enhanced binding constant for platinated nucleobases. This was confirmed by density functional theory (DFT) calculations as the difference in energy between the HOMO of Trp and the LUMO of the nucleobase was smaller for the platinum complex. The studies were extended to the Trp-containing C-terminal ZF of HIV1 NCp7 and an increase in association constant was seen compared to free Trp. Reaction of PtN4 nucleobases compounds with a short amino acid sequence con- taining either Ala (no pi-stacking capabilities) or Trp (pi-stacking interactions) revealed an enhanced rate of reactivity for the Trp-containing peptide. This result supports the theory of a two-step reaction mechanism where the platinum-nucleobase complex recognizes the pep- tide through a pi-stacking interaction with Trp followed by covalent binding to the platinum center. The [Pt(dien)L]2+ motif allows for systematic modification of the structural elements surrounding platinum in a search for the most effective compound. Methylation of the dien ligand should, in theory, increase lipophilicity of the compounds, however, due to 2+ charge of the compounds, this simple association does not hold true. Analysis of the cellular accumulation profiles showed little change in the uptake with the addition of methyl groups to the dien ligand, in agreement with the non-linear change in lipophilicity. Modification of L using different nucleobases allows for the tuning of the strength of the π-stacking interaction between Trp and the platinum complex. The addition of inosine (which lacks a H-bonding donor/acceptor at the C2 position) resulted in a lower association constant with both N-AcTrp and the C-terminal zinc finger of HIV1 NCp7. Interestingly, the addition of xanthosine resulted in an ehanced pi-stacking interaction with the C-terminal zinc finger of HIV1 NCp7; likely as a results of the addition of a H-bonding donor (double-bonded O) at the C2 position. The ability of PtN4 nucleobase complexes to inhibit formation of the NCp7 complexation with viral RNA was studied by mass spectrometry and gel electrophoresis. Dissociation of the NCp7-RNA complex was seen upon addition of PtN4 compounds. These compounds were also able to retard formation of the NCp7-RNA complex when pre-incubated with the protein. These results have important implications as inhibition of complex formation between NCp7 and viral RNA has negative implications for viral replication. Despite the success of platinum-nucleobase compounds, it is important to evaluate all potential pi-stacking ligands. A series of pyridine- and thiazole-based compounds were evaluated for the strength of the pi-stacking interaction with N-AcTrp and the C-terminal ZF of HIV1 NCp7. There was notable increase in association constant for the platinum- DMAP (4-dimethylaminopyridine) complex compared to other ligands studied. This result highlights the importance of exploring multiple avenues for the design of specifically targeted inhibitors and further confirms the viability of the medicinal chemistry dual approach of target recognition (non-covalent) followed by target fixation (covalent).
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Fashina, Adedayo, and Tebello Nyokong. "Nonlinear optical response of tetra and mono substituted zinc phthalocyanine complexes." Elsevier, 2015. http://hdl.handle.net/10962/d1020318.
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The nonlinear absorption properties of 6 mono-substituted and 3 symmetric zinc phthalocyanine complexes have been studied in dimethylsulfoxide (DMSO) using 10 ns pulses at 532 nm. The non linear absorption of the complexes has been studied using the Z-scan technique. The study showed that both the singlet and triplet excited states contribute to the non linear absorption behavior. The nonlinear third-order susceptibility and second-order hyperpolarizability values of the complexes are reported. It was observed that two of the symmetric phthalocyanine complexes (5-α substituted with aminophenoxy and 9-β substituted with carboxyphenoxy) showed better and promising optical nonlinearity when compared to the other complexes studied.
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Day, Alex. "Gas Chromatography Analysis of CO2 Reduction Photocatalysis with Zinc Dipyrrin Complexes." Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/honors/498.
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Bis(1,3,7,9-tetramethyl-5-mesityldipyrrinato)zinc(II) (ZnDPY) was synthesized in the lab by the McCusker group and a procedure was created to analyze its ability as a photosensitizer, a molecule that provides the energy for the reaction to occur by capturing light energy and turning it into a form that can be used by the photocatalyst. While more work is needed, preliminary steps have been made to create a process that can analyze the amount of carbon monoxide produced by a photocatalytic CO2 reduction reaction with ZnDPY as the photosensitizer. Progress has been made via the setup of a reaction apparatus, targeted gas chromatography (GC) peak separation, and GC calibration. More work will need to be done in order to determine the optimal reaction mix to showcase the sensitizer’s potential.
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Alqahtani, Norah. "Synthesis and Characterization of Zinc(II) Dipyrrin Photosensitizers." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3466.
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Photocatalytic carbon dioxide reduction transforms CO2 to useful chemicals and fuels, reducing CO2 emissions and making fossil fuels more renewable. Due to a lack of earthabundant sensitizers, we want to design new earth-abundant sensitizers to go with the many known carbon dioxide reduction catalysts. Zn(II) dipyrrin complexes strongly absorb visible light, but their excited state properties have not been widely studied. To investigate their photophysical properties, two Zn dipyrrin complexes, with and without heavy atoms, were synthesized and characterized by NMR and mass spectrometry. The photophysical properties of the two complexes were measured in polar and non-polar solvents, particularly fluorescence quantum yield and extinction coefficient. Also, through transient absorption spectroscopy, the triplet state quantum yield of both complexes was measures to determine the effect of solvent polarity and heavy atoms on the triplet state formation.
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Doyle, David Joseph. "Novel zinc and chromium complexes for the copolymerisation of epoxides with CO2." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497672.
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Bwembya, Gabriel Chewe. "Chalcogenolato complexes of zinc and cadmium as precursors for solid-state material." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261044.
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Bradshaw, Darren. "Towards structural analogues of metallobiosites : synthesis and characterisation of dinuclear zinc complexes." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369959.
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Bette, Virginie Andrée Marie. "Hydrosilylation asymétrique de cétones fonctionnalisées avec le PMHS : utilisation de complexes de zinc." Lille 1, 2003. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/bcf89cbb-550b-448b-ad77-f5df2e3d7a05.
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L'hydrosilylation asymétrique est une voies d'accès aux alcools et amines énantiopurs. Bien que très efficace, le coût et la toxicité des réducteurs silanes associés limite son application industrielle. Notre étude a porté sur le développement d'un système catalytique associant le zinc à des diamines et utilisant le PMHS, hydrosilane peu cher, stable et nontoxique. En milieu aprotique, la réduction d'alkylarylcétones s'effectue avec de hautes cbimio- et énantiosélectivités. La synthèse de nouvelles 1,2-diamines a permis d'atteindre 91 % d'excès énantiomérique sur l'acétophénone. Les substrats polyfonctionnels sont cependant difficilement réduits dans le toluène. A l'opposée, ce système est efficace en milieu protique sur une large gamme de substrats (alkylarylcétones, α- et β-cétoesters, cétoamides et imines). La procédure de réduction simple en une étape mène à d'excellentes activités et chimiosélectivités, les énantiosélectivités restant toutefois modestes (15-48 %). Divers précurseurs catalytiques simples et peu chers, tels que Zn(OMe)2ou Zn(OH)2,peuvent être employés. L'étude des mécanismes en milieu aprotique/protique a conduit à la synthèse et à l'étude de la réactivité de nouveaux complexes de zinc, proposés comme intermédiaires réactionnels ) pour expliquer les réactivités inhabituelles en milieu protique.
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de, Rosales R. T. M. "Zinc(II) complexes with internal hydrogen bonding interactions : towards more efficient synthetic nucleases." Thesis, University of Edinburgh, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.649255.
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A series of zinc(II) complexes of tripodal ligands resembling the catalytic zinc sites of nucleases have been synthesised and fully characterised. Some of these complexes were used to explore strategies to induce the hydrogen bond interactions that influence the catalytic performance of nucleases, and to investigate the factors that affect their strength. X-ray diffraction, NMR and IR studies revealed the formation of hydrogen bonding interactions between amide/amine groups and other zinc-bound ligands both in solution and in the solid state. We have been able to estimate the energies of these hydrogen bonds by IR and VT <sup>1</sup>H NMR coalescence studies. From this work, it appears that metal-ligand bonding may be as important as the nature of the hydrogen bond donors and acceptors towards defining the geometry and strength of the hydrogen bond formed. We have investigated the effect of different hydrogen bonding microenvironments on structural features of trigonal bipyramidal [(L)Zn(Cl)]<sup>+</sup> cations. Among the implications of introducing hydrogen bonding groups is the lengthening of the axial Zn-Cl and equatorial L-Zn bonds. This structural study may facilitate future structure-function relationships. We have also investigated the effect of these hydrogen bonding microenvironments in the acidity of a zinc(II)-bound water molecule, which is a key parameter of catalytic zinc sites. Thus, from potentiometric titrations it appears that amino hydrogen bonding groups adjacent to a zinc(II)-bound water molecule enhances its acidity as much as 1 p<i>K</i><sub>a</sub> unit per hydrogen bonding group. The results presented in this work provide important insights into the possible role(s) of the active site microenvironment in modulating the zinc(II)-promoted hydrolysis of nucleic acids and may contribute to the development of more efficient synthetic nucleases.
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Li, Zhe. "Fluorinated zinc and erbium complexes based on benzothiazole derived ligands for optoelectronic devices." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8547.
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Three families of fluorinated ligands based on benzothiazole derivatives, including 2-(2-hydroxyphenyl)benzothiazoles, bis(benzothiazolyl)amines and N-benzothiazol- 2-yl-methanesulfonamides, have been synthesised with different locations and extents of fluorination. Zinc complexes of the fluorinated 2-(2-hydroxyphenyl)benzothiazoles and bis(benzothiazolyl)amines have been successfully prepared. Crystallographic characterisations of these zinc complexes have revealed various molecular packing behaviours in their crystals in terms of πH-πH, πH-πF and πF-πF stacking under the influence of partial and complete fluorination. DFT calculations and photophysical studies of these complexes have demonstrated that fluorination of these molecules decreases their HOMO and LUMO levels simultaneously by about the same amount, roughly 0.1 eV per substitution of hydrogen by a fluorine atom. An inverse correlation has been found between the dihedral angles of conjugating aromatic rings and the photoluminescence full width at half maximum (FWHM), which could be one of the reasons for the broadening of photoluminescence spectra upon fluorination. The applications of the zinc complex of 2-(2-hydroxy-3,4,5,6- tetrafluorophenyl)-4,5,6,7-tetrafluorobenzothizole (Zn(F-BTZ)2) in organic light emitting diode (OLEDs) have been investigated. The electroluminescence of Zn(F-BTZ)2 has shown remarkable phosphorescence in the red region, indicating enhanced spin mixing and intersystem crossing introduced by the substitution of the hydrogen atoms by the higher atomic number fluorine atoms. This ability of providing a large population of triplets, together with the lack of CH or OH oscillators of this perfluorinated Zn(F-BTZ)2 molecule, allowed its use as an efficient chromophore to sensitise the erbium ions in a long-lifetime erbium complex, erbium (III) tris (pentafluorophenyl)imidodiphosphinate (Er(FTPIP)3). By doping Er(FTPIP)3 into Zn(F-BTZ)2 in the OLED, we achieved significant and long-lifetime emission from erbium at the important telecommunication wavelength of 1.5 μm.
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Salvagni, Emiliano. "Mononuclear zinc(II) complexes with intramolecular hydrogen bonding interactions as models of peptidases." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/11359.
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As an approach to explore the amide cleavage reaction, we designed, synthesised, fully characterised and investigated different model systems resembling the catalytic zinc sites of peptidases. The models are mononuclear zinc(II) complexes containing the unit (6-NHR-2-pyridylmethyl)amine (R = CO<sup>t</sup>But, H) as a common feature. This unit supplies an N2 coordination motif and an intramolecular amide oxygen capable of binding the metal ion (Zn<sup>…</sup>O=C(amide)); such event has been proposed to be crucial for the cleavage of peptide bonds in peptidases. Besides, these models offer different types and numbers of metal binding sites, which affect electronically and sterically the zinc(II) ion as well as its Lewis acidity. Indeed, the effect of the first coordination sphere seems to influence drastically the cleavage of the intramolecular amide bond leading to an overall change in the stability of the amide bond of <i>ca. </i>300-fold. The unit (6-NHR-2-pyridylmethyl)amine also provides amide/amine groups that can hydrogen bond other zinc-bound ligands. Some of these complexes were, therefore, used to explore strategies to induce and manipulate hydrogen bond interactions, and to investigate the factors that influence their strength. These hydrogen bond interactions occur both in solution and in the solid state and their strength was determined by IR spectroscopy and correlated with the X-ray crystal structures. We also report two strategies to position NH groups in the proximity of a zinc(II)-bound amide oxygen N-H<sup>…</sup>O=C(amide), and we investigate their effect on the stability of the amide group.
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Jamadar, Abeda. "Copper(II) and Zinc(II) complexes of aroyl hydrazones as potential antitubercular agents." Thesis, University of York, 2012. http://etheses.whiterose.ac.uk/3099/.
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There is a continuing need to make new antitubercular drugs due to development of resistance towards present drugs. To do this, series of pyruvate hydrazones (PVAHs) and their respective Cu(II) complexes and Zn(II) complexes were synthesized and fully characterised. Variable temperature NMR studies of PVAHs indicate the presence of E and Z isomers in the solution. Determination of the obtained single crystal X-ray structures reveals that Cu(II) ion binds to PVAH ligand in 1:1 ratio resulting in square pyramidal geometry in most of the Cu(II) complexes, whereas Zn(II) ion binds to two PVAH ligands in 1:2 ratio giving rise to octahedral geometry. The electrochemical studies of Cu(II) complexes of PVAH performed using cyclic voltammogram indicate the presence of quasi-reversible behaviour assigned to a Cu2+/Cu1+ peak potential. This indicates structural reorganisation of Cu(II) square pyramidal geometry towards Cu(I) tetrahedral geometry. The tetrahedral geometry of a synthesized Cu(I) complex of PVAHs was confirmed by X-ray crystal structure. The stability studies of selected PVAH ligands and their metal complex indicate that the investigated compounds were stable in extreme basic conditions, but they were unstable in extreme acidic conditions due hydrolysis of azomethine bond. However, stability of these compounds in physiological conditions, i.e. in PBS buffer, reveals that ligand hydrolyses slowly over a period of time, whereas the Cu(II) complex remains quite stable over a monitored period of 120 hours. Interestingly, dihydrazide analogue of PVAH was fairly stable in PBS buffer. EPR studies of investigated Cu(II) complexes in DMSO indicate that PVAHs remains strongly coordinated to Cu(II) centre. The evaluation of the antimycobacterial activity showed that the anionic PVAHs and Zn(II) complexes are essentially inactive. Some of the corresponding neutral Cu(II) complexes, however, exhibit promising antimycobacterial activities if tested under high iron (8 μg Fe per mL) conditions. As observed for the related antimycobacterial agent isoniazid, the activity of the complexes decreases if the M. tuberculosis cells are grown under low iron (0.02 μg Fe per mL) conditions. The Cu(II) complexes may thus have a similar mode of action and may require an iron-containing heme-dependent peroxidase for activation. A series hydrophobic cinnamaldehyde hydrazones (CAHs) and their Cu(II) complexes were also synthesized and tested for their antitubercular activity under similar conditions to that of PVAH series. But they failed to show any inhibitory activity due to their poor cellular uptake owing to their limited solubility in aqueous buffer.
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Amatore, Muriel Gosmini Corinne. "Synthèse de liaisons carbone-carbone via l'utilisation d'une catalyse par des complexes du cobalt." Créteil : Université de Paris-Val-de-Marne, 2006. http://doxa.scd.univ-paris12.fr:8080/theses-npd/th0252093.pdf.
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Thèse de doctorat : Chimie organique : Paris 12 : 2006.<br>Version électronique uniquement consultable au sein de l'Université Paris 12 (Intranet). Titre provenant de l'écran-titre. Pagination : 231 p. Bibliogr. : 328 réf.
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Visscher, Arne. "Fluorescence Studies of Amine-substituted Azaanthracene Metal Complexes." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2016. http://hdl.handle.net/11858/00-1735-0000-0028-87CC-A.
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Dzaye, Irene Yayra. "The Contribution of Charge Separation in Triplet State Formation in Zinc Dipyrrin Photosensitizers." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/asrf/2020/presentations/34.
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About 85% of the world’s energy is derived from non-renewable sources—coal, petroleum, and natural gas. Solar photocatalysis is one way to potentially generate renewable fuels. Zinc dipyrrin complexes have the potential to be efficient sensitizers for reductive photochemistry, but their ability to form long-lived triplet excited states needs further investigation. The overall aim of this research is to compare the photophysical properties zinc and boron dipyrrin complexes and investigate the role of the charge separated state in triplet state formation. This presentation will describe the synthesis and purification of zinc and boron dipyrrin complexes and their photophysical characterization, including fluorescence quantum yields in a series of solvents and their emission at low temperatures.
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Rodopoulos, Theo. "An equilibrium and kinetic study of cryptand, lariat ether and fluorescent zinc (II) complexes /." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phr695.pdf.
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Steinborn, Martin. "Coordination chemistry of sugar-phosphate complexes with palladium(II), rhenium(V) and zinc(II)." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-161901.
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Wheaton, Craig Andrew. "The development of cationic zinc complexes as a new class of lactide polymerization catalyst." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Chemistry and Biochemistry, 2011, 2011. http://hdl.handle.net/10133/3108.
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The thesis outlines the development of novel cationic zinc complexes for application in lactide polymerization catalysis. These complexes were characterized spectroscopically and crystallographically, and where appropriate their efficacy as catalysts for the polymerization of lactide was evaluated.
The strongly donating, neutral chelating ligands employed in this study were prepared by installation of either one or two phosphinimine donors on a dibenzofuran backbone. An efficient synthetic methodology was then developed for the synthesis of cationic complexes of the formula [LZnE+][BAr4-], wherein E = C2H5, CH3, Ph, C6F5, OAc, OC6F5, or methyl-(D,L)-lactate, and AR = Ph, C6F5, or m-(CF3)2-C6H3. Only the cationic zinc-lactate species were found to be highly active polymerization catalysts.
Tuning of the steric and electronic properties of the ligand resulted in the discovery of zinc-lactate systems that promote rapid and well-controlled polymerization of lactide under mild conditions, marking the first well-defined cationic metal catalysts to do so.<br>xxiv, 254 leaves : ill. ; 29 cm + 1 CD-ROM
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Torres, Martin de Rosales Rafael. "Mononuclear zinc(II) complexes with intramolecular hydrogen bonding interactions : towards more efficient synthetic nucleases." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/14558.
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Brooks, Anthony. "The Photon Driven Reduction of Zn(II) to Zinc Metal by Transition Metal Complexes." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/1048.
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The photon driven reduction of Zn(II) to zinc metal is a novel field of study with many potential applications including the use of zinc metal as a solar fuel. Although it has not been widely considered for such a role in the past, zinc is an appealing means to store solar energy as a stable fuel without the safety risks of hydrogen gas. As a solar fuel, zinc metal would be used in efficient zinc air batteries and then regenerated by the photocatalytic reduction of Zn(II) and a concurrent oxidation reaction. In this vein, this work reports the photocatalytic reduction of Zn(II) to zinc metal using visible light. Heteroleptic bis-cyclometallated iridium complexes and zinc quinolates that form in situ are found to be effective photocatalysts. Zinc generating photoreactions are conducted on a custom-designed home-built photoreactor, with triethylamine (TEA) employed as the sacrificial reductant. Photocatalyst structure–activity relationships, ideal reaction conditions, and reaction kinetics are described for the iridium catalyzed reaction. Cyclic voltammetry of zinc salts is used to supplement the investigation of the Zn(II) reduction mechanism. A maximum of 430 catalyst turnovers is reported. Similar experiments are performed in order to characterize the zinc quinolate catalyzed reduction of Zn(II) and confirm aspects of the reaction mechanism. Additionally, fluorescence quenching and 1H NMR titration experiments are employed to identify the zinc quinolate that forms in situ from 5,7-dichloro-8-hydroxyquinoline. Subsequently, ligands with extended conjugated pi systems relative to 8-hydroxyquinoline are synthesized and their photocatalytic activity is assessed. Second generation iridium photocatalysts with bridging nitrile functionalities are also synthesized and evaluated in an attempt to improve catalytic activity.
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Eustermann, Sebastian. "Structural insights into eukaryotic DNA damage response from NMR studies of unusual zinc finger complexes." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609361.
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Wezenberg, Sander Johannes. "Exploring metallosalen complexes in materials science and catalysis." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/37357.
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Los complejos “metalosalen” [salen = N,N’-bis(salicilideno)etilendiamina] han sido objeto de estudio en la catálisis homogénea y últimamente también en la ciencia de materiales y catálisis multimetálica. En cuanto a esto, hemos explorado el potencial de los complejos “salfen” [N,N’-bis(salicilideno) fenilendiamina] centrados en Zn(II) como componente en el desarrollo de nuevos materiales y sistemas multimetálicos. Los primeros capítulos de esta tesis proporcionan una mejor comprensión sobre las propiedades de estos complejos y esto es seguido por aplicación como detector quiral y estudios de comportamiento de autoensamblaje. Los últimos capítulos se centran en sistemas metalosalen multimetálicos mediante enfoques supramolecular y covalente para su aplicación en la catálisis cooperativa. Este tesis demuestra el potencial de los compuestos salen para su aplicación en ciencia de materiales y catálisis cooperativa.<br>Metallosalen complexes [salen = N,N’-bis(salicylidene)ethylenediamine] have been well-studied in homogeneous catalysis and lately reveive inceasing interest in materials science and multimetallic catalysis. In view of this, we have explored the potential of Zn(II)-centered salphen [N,N’-bis(salicylidene)phenylenediamine] complexes as a building block in the development of new materials and multimetallic systems. The first chapters of this thesis provide a better understanding of the properties of these complexes and this is followed by application as a chiral sensor and studies of their self-assembly behavior. The last chapters focus on multimetallic metallosalen systems for application in cooperative catalysis using supramolecular and covalent approaches. This thesis illustrates the potential of metallosalen complexes for application in materials science and cooperative catalysis
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Wambua, Pasco M. "Synthesis and Characterization of Monomeric Magnesium and Zinc complexes supported by 1,5,9-Trimesityldipyrromethene for use in polymerization studies." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1308265029.
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Fry, Fiona Helen 1972. "Metal complexes based on macrocyclic ligands and their ability to hydrolyse phosphate esters." Monash University, School of Chemistry, 2002. http://arrow.monash.edu.au/hdl/1959.1/8279.
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Parrot, Arnaud. "Systèmes supramoléculaires biomimétiques : les complexes bols, synthèse, propriétés et réactivité." Thesis, Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCB153/document.
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Le ligand Rim3, constitué d’une cavité resorcinarène fonctionnalisée par 3 groupements méthylimidazole a été synthétisé et étudié. Ce ligand est capable de coordiner différents métaux de transitions comme le zinc et le cuivre. Ces complexes possèdent des propriétés hôte-invité intéressantes et une sélectivité avec la taille de la cavité. La complexation d’invités acides nécessite l’addition d’une base exogène. De plus, la présence de base peut être nécessaire pour réaliser des réactions d’hydratation ou d’hydrolyse. Dans ce manuscrit sont présentés différents ligands cavitaires resorcinarène avec 4 imidazoles greffés. Chaque ligand et complexe associé présente des solubilités différentes. Nous étudierons d’abord la synthèse et la caractérisation des systèmes en milieu organique ou aqueux. Les études de complexation montreront la forte affinité associée à ces complexes en milieu organique. L’étude des propriétés hôte-invité montre que le complexe est capable de coordiner un invité acide de manière quantitative dans les conditions RMN. Cette coordination ne nécessite pas l’addition de base. Le 4e imidazole joue le rôle de base intramoléculaire et n’est pas nécessaire à la coordination. Deux positions labiles en cis sont également disponibles, attesté par la coordination de ligands bidentes. Le complexe zincique [Rim4ZnII(EtOH)](ClO4)2 montre des propriétés d’hydratation des nitriles. Dans l’acétonitrile avec 35% d’eau à 70°C, le complexe forme de l’acétamide de manière catalytique. L’addition de base n’est pas nécessaire et le pH n’évolue pas avec la réaction. Dans l’eau avec 10% d’acétonitrile, [WRim(OH)44 Zn(H2O)](NO3)2 catalyse l’hydratation en acétamide mais est inhibé par l’hydrolyse successive en acétate<br>In this manuscript, we present the synthesis and caracterisation of three tetradentate bowlshaped ligand. These ligands are resorcin[4]arene functionnalized by four methylimidazole. Each ligand is soluble in a different medium, such as organic solvent, water and mixed solvent. The four methylimidazoles are able to coordinate several metal ions, such as zinc, copper and iron. We then present the host-guest properties of the complexes. The complexes are able to coordinate acidic guests without addition of an exogenous base, thanks to the fourth imidazole. Two labiles positions are avalaible in cis, and bidentate ligands are able to coordinate the metal ions. Finally, we present the reactivity of the complexes. The zinc complex, [Rim4Zn]2+ catalyses the acetonitrile hydration with 35% water at 70°C. In an aqueous media with 10% water,[WRim(OH)44 Zn(H2O)](NO3)2 catalyses not only the acetonitrile hydration but also it’s subsequent hydrolysis into acetate
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Beitat, Alexander [Verfasser]. "Investigations on the behavior of zinc and copper complexes containing polydentate amine ligands / Alexander Beitat." Gießen : Universitätsbibliothek, 2012. http://d-nb.info/1064990703/34.
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REIS, ALINE CRUZ DE MORAES. "SYTHESIS AND CHARACTERIZATION OF COPPER (II) AND ZINC (II) COMPLEXES WITH DIPEPTIDES OF BIOLOGICAL INTEREST." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=16186@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO<br>Este trabalho descreve a síntese e caracterização de quatro complexos de cobre (II) e quatro complexos de zinco (II), com dipeptídeos, no estado sólido. Os dipeptídeos envolvidos foram: glicil-glicina, glicil-valina, metionil-metionina, metionil-glicina e cisteinil-glicina, cujos aminoácidos fazem parte de algumas proteínas envolvidas em processos de neurodegeneração, mais especificamente na doença de Alzheimer. Embora os mecanismos que desencadeiam esta patologia não estejam ainda totalmente esclarecidos, sabe-se que os íons metálicos, como o cobre (II) e o zinco (II), interagem com o peptídeo beta-amilóide. Acredita-se que tais interações favoreçam a formação de agregados protéicos sólidos deste peptídeo, observados nos cérebros de pacientes com essa doença. Dessa forma, a obtenção e o estudo de modelos simples no estado sólido, sintetizados em condições próximas ao meio biológico, podem permitir uma melhor compreensão de possíveis interações de tais metais neste sítio protéico. Os compostos obtidos foram caracterizados utilizando as seguintes técnicas: análise elementar, absorção atômica, espectroscopia de infravermelho, espectroscopia Raman, espectroscopia de ultravioleta-visível, termogravimetria, RPE (para os complexos de cobre) e condutivimetria. Para os complexos de zinco, foram realizados cálculos teóricos mecânico-quânticos para obtenção de parâmetros geométricos e espectros de infravermelho. A análise dos compostos obtidos mostrou que os complexos de cobre e zinco com os dipeptídeos estão coordenados por átomos de oxigênio e nitrogênio. Nos complexos de peptídeos contendo enxofre, a coordenação também ocorre pelo átomo de enxofre (cobre com metionil-metionina e metionil-glicina e zinco com cisteinil-glicina). Os compostos obtidos para ambos os metais na proporção metal-ligante (1:1) mostram comportamento diferente dos estudos em solução e aqueles obtidos na proporção metal-ligante (1:2) mostram comportamento similar a complexos de metais com aminoácidos.<br>This work describes the synthesis and characterization of copper (II) and zinc (II) complexes, with dipeptides in solid state. The dipeptides involved were:
glycyl-glycine, glycyl-valine, methionyl-methionine, methionyl-glycine and cysteinyl-glycine, whose aminoacids take part in some proteins involved in neurodegeneration processes, more specifically in Alzheimer’s disease. Although the mechanisms that trigger this pathology are still not totally clear, it is known that metallic ions, such as copper (II) and zinc (II) interact with the beta-amyloid peptide. It seems that such interactions favor the formation of solid proteic aggregates of this peptide, observed in the brains of patients with Alzheimer’s disease. Thus, the obtaining and study of simple models in the solid state, synthesized in similar conditions to the biological medium, may allow a better understanding of the possible interactions of such metals in this proteic site. The compounds obtained were characterized using the following techniques: elemental analysis, atomic absorption, infrared spectroscopy, Raman spectroscopy, ultraviolet-visible spectroscopy, thermogravimetry, EPR (for the copper complexes) and conductivimetry. For the zinc complexes, quantum-mechanical theoretical calculations were performed to obtain geometrical parameters and infrared spectra. The analysis of the compounds showed that the copper and zinc complexes with dipeptides are coordinated through oxygen and nitrogen atoms. In complexes of dipeptides containing sulfur, coordination trough the sulfur atom occurs too (copper with methionyl-methionine and methionyl-glycine and zinc with cysteinyl-glycine). The compounds obtained for both metals at the metal-ligand ratio (1:1) behave differently from those studied in solution e those obtained in the metal-ligand ratio (1:2) show similar behavior of metal complexes with aminoacids.
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SZYFMAN, NATALIE WAISSMANN. "STUDY OF COPPER(II) AND ZINC(II) COMPLEXES WITH SOME POLYAMINES AND PHOSPHOCREATINE OR ATP." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=18244@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>Foram estudados alguns sistemas binários de Cu(II) e Zn(II) formados com as poliaminas (PA= En, Tn, Put, Spd e Spm) e os complexos ternários (MLPA), onde L foi a PCr ou o ATP e PA uma das cinco poliaminas. O estudo foi realizado em solução aquosa por potenciometria, espectroscopia de ultravioleta-visível, Raman, RMN e RPE e cálculos de menor energia de estabilização e modelagem molecular. As constantes de estabilidade foram determinadas pela potenciometria. Os valores das constantes dos complexos com as poliaminas apresentam um comportamento bastante diferenciado entre os sistemas formados com o Cu(II) e Zn(II). A ordem dos valores das constantes de estabilidade dos sistemas com o Cu(II) é:CuPut<CuTn<CuEn<CuSpd<CuSpm, e dos sistemas com Zn(II) é: ZnPut<ZnEn<ZnTn<ZnSpm<ZnSpd. Esse comportamento diferenciado se deve a estrutura formada nos complexos. Enquanto o anel de 5 membros formado pelo complexo CuEn é mais estável do que o anel de 6 e 7 membros formados pelos complexos CuTn e CuPut, respectivamente, nos sistemas com o Zn(II) o complexo que forma anel de 6 membros (ZnTn) é mais estável do que o complexo que forma anel de 5 membros (ZnEn). Já o complexo ZnPut é o menos estável pela coordenação monodentada da poliamina ao Zn(II). Os complexos formados com Cu(II) e Zn(II) com a Spd e Spm também apresentam comportamento diferenciado. Com o Cu(II) as poliaminas Spd e Spm formam complexos se coordenando com três e quatro grupamentos amino, respectivamente. Com o Zn(II) a coordenação deve ser por três grupamentos amino nos dois complexos formados. Interações entre as poliaminas protonadas e os dois ligantes são observadas de um modo geral exceto no sistema Zn:ATP:Spd, e isso se deve a conformação que a molécula formada sofre que desfavorece a interação entre os ligantes. Interações entre as triamina (Spd) e tetramina (Spm) e a PCr, são observadas nos complexos ternários, para ambos os íons, mesmo quando estas não estão protonadas. Esta interação deve ser pelo átomo de nitrogênio não coordenado da poliamina e o átomo de oxigênio não coordenado da PCr. Neste trabalho foi possível esclarecer o modo de coordenação do Cu(II) com a PCr em solução, que é pelos grupamentos guanidino e fosfato do ligante, tanto no complexo binário como nos complexos ternários. Também para o Zn(II) a PCr se complexa do mesmo modo. O modo de coordenação do ATP ao Zn(II) tanto nos complexos binários como ternários, deve ser através dos grupamentos fosfatos PB e Py .<br>Some binary systems of Cu(II) and Zn(II) with polyamines (PA=En, Tn, Put, Spd and Spm), and ternary complexes (MLPA) of Cu(II) and Zn(II), where L is PCr or ATP, and PA is one of the five polyamines, were studied. The study was performed in aqueous solution using potentiometry, ultraviolet-visible, Raman, NMR and EPR spectroscopies, and, calculations of the lowest stabilization energy for formed complexes and molecular modeling. The stability constants were determined by potentiometry. The order of the values of stability constants of the systems with Cu(II) is: CuPut<CuTn<CuEn<CuSpd<CuSpm. For systems with Zn(II) it is: ZnPut<ZnEn< ZnTn<ZnSpm<ZnSpd. This different behavior is due to the structures formed by the complexes. While the 5-membered ring formed by CuEn complex is more stable than the 6- and 7-membered ring complexes formed by CuTn and CuPut, respectively, in systems with Zn(II) the complex that forms the 6-membered ring (ZnTn) is more stable than 5-membered ring (ZnEn). The complex ZnPut is less stable than systems formed with other diamines, suggesting a monodentate coordination of this polyamine with Zn(II). The complexes formed by Cu(II) and Zn(II) with Spd and Spm also have a peculiar behavior. With Cu(II) the polyamines Spd and Spm form complexes by coordinating with three and four amino groups, respectively. With Zn(II) coordination should be through three amino groups in both complexes. Interactions between protonated polyamines and the two ligands are generally observed, except in the system Zn:ATP:Spd. This can be because of the conformation suffered by the molecule, hindering the interaction between the ligands. Interactions between the tridentate (Spd) and tetradentate (Spm) polyamines and PCr are observed in the ternary complexes for both ions, even when the PA´s are not protonated. This interaction should be between the non-coordinated nitrogen atom from the PA and the non-coordinated oxygen atom from PCr. It was possible to clarify the coordination mode of Cu(II) with PCr in solution, which occurs through the guanidine and phosphate groups of PCr, both in the binary and ternary complexes. The ion Zn(II) also coordinates in the same way. The coordination mode of ATP with Zn(II) in the binary and ternary complexes probably takes place through the PB and PY phosphates groups.
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DETERS, ELIZABETH ANN. "Novel Dinucleating Poly(oxime) Amine Ligands and their Nickel and Zinc Complexes: Oxygen and Hydrolysis Reactivity." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1180644861.
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Al-Abdullah, Khalaf. "Contribution à l'étude du comportement des varistances à base d'oxyde de zinc, par la mesure des impédances complexes à basse et à moyenne fréquences." Toulouse 3, 1991. http://www.theses.fr/1991TOU32310.
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Ce travail montre que la representation des impedances complexes des varistances a base de zno, dans le plan de nyquist, pour les frequences de 10##3 a 7. 10#6 hz, donne des arcs de cercles ayant leur centre sur l'axe des reels lorsque t est inferieur a 120c, en accord avec le modele de debye et en dessous de cet axe pour t superieur conformement au modele empirique de cole-cole. Il met en evidence que cette mesure est une methode permettant d'estimer la resistance, rcc, en courant continu et de determiner la resistance de grains rg (0,03 ohm), les energies d'activation, le facteur d'heterogeneite du materiau et le temps de relaxation. Ce dernier parametre diminue si les temperatures de mesures augmentent ainsi qu'apres l'application d'impulsions de forte energie. Par contre, le facteur d'heterogeneite croit lorsque t augmente et apres degradation. La variation de ces parametres caracterisant la varistance est due au changement de la concentration des donneurs et a celui des etats de surface (pieges) responsables de la formation de la barriere de schottky. Cette methode est appliquee a l'etude des processus de degradation des varistances. Elle etablit une correlation entre les parametres de l'impedance et les caracteristiques j-e. En effet, elle montre, apres degradation, que le courant de fuite et le facteur d'heterogeneite augmentent; par contre, la hauteur de barriere et la constante de temps diminuent. L'analyse de la fonction de distribution des temps de relaxation, determinee par cette methode, permet d'evaluer le degre d'homogeneite des barrieres dont dependent les proprietes electriques de la varistance
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Amatore, Muriel. "Synthèse de liaisons carbone-carbone via l'utilisation d'une catalyse par des complexes du cobalt." Paris 12, 2006. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990002520930204611&vid=upec.
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Ce travail de thèse est consacré à l'utilisation de sels de cobalt (II), associés ou non à des ligands de type 2,2'-bipyridine ou triphénylphosphine, pour la réalisation de réactions de couplage croisé de manière directe, par voie purement chimique. Ces réactions mettent en jeu des hallogénures ou pseudo-hallogénures aromatiques et hétéroaromatiques, ainsi que des réctifs divers comme les acétates vinyliques, les oléfines activées ou encore des hallogénures d'alkyle. Toutes ces réactions impliquent des espèces organométalliques catalytiques de type aryl-cobalt. Ces intermédiaires catalytiques nous permettent alors d'orienter nos réactions soit pricipalement vers la synthèse directe de liaisons carbone-carbone, soit vers la formation d'arylzinciques, que nous avons pu obtenir à partir des chlorures aromatiques correspondants. Ce manuscrit, divisé en quatre chapitres, présente les résultats que nous avons pu obtenir au cours de ce travail. L'utilisation de différents systèmes catalytiques tels que COBR2(BPY) ou COBR2(PPH3) associés au manganèse comme métal réducteur, ou bien COBR2(BPY) ou COBR2 associés au zinc, nous a permis de développer des réactions de vinylation (chapitre I), d'addition conjuguée (chapitre II), d'alkylation via le passage par un organozincique ou non (chapitre III) et enfin de synthèse de biaryles dissymétriques (chapitre IV)<br>This work is devoted to the realization of direct chemical cross-coupling reactions, using cobalt (II) salts associated to 2,2'-bipyridine or triphenylphosphine. These reactions involve aromatic or heteroamromatic halides or pseudo-halides, as well as a broad range of reagents such as vinylic acetates, activated olefins or alkyl halides. All these cross-coupling reactions are based on the formation, in catalytic amounts, of organometallic derivatives, the aryl-cobalt species. These catalytic intermediates allow us to direct the reactions either mainly towards carbon-carbon bond formation or towards the synthesis of arylzinc reagents, that we obtained in good yields strating from the corresponding aromatic chlorides. This manuscript, divided into four chapters, presents the results we obtained during this research work. The use of various catalytic systems such as COBR2(BPY) or COBR2(PPH3) in association with manganese as reductant, or else COBR2(BPY) or COBR2 in association with zinc powder, allowed us to develop vinylation reactions (chapter I), conjugate addition reactions (chapter II), alkylation reactions via an organozinc reagent or not (chapter III) and lastly, non symetric biaryls synthesis (chapter IV)
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Deters, Elizabeth Ann. "Novel dinucleating poly(oxime) amine ligands and their nickel and zinc complexes oxygen and hydrolysis reactivity /." Cincinnati, Ohio : University of Cincinnati, 2007. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1180644861.
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Thesis (Ph. D.)--University of Cincinnati, 2007.<br>Title from electronic thesis title page (viewed Oct. 8, 2007). Includes abstract. Keywords: nickel, dinuclear, oxime, zinc, hydrolysis. Includes bibliographical references.
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Steinborn, Martin [Verfasser]. "Coordination Chemistry of Sugar-Phosphate Complexes with Palladium(II), Rhenium(V) and Zinc(II) / Martin Steinborn." München : Verlag Dr. Hut, 2013. http://d-nb.info/1042878439/34.
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Dzaye, Irene Yayra. "Investigating The Role of Charge Separation in Triplet State Formation in Zinc Dipyrrin Photosensitizers." Digital Commons @ East Tennessee State University, 2021. https://dc.etsu.edu/asrf/2021/presentations/28.
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About 85% of the world’s energy is derived from non-renewable sources—coal, petroleum, and natural gas. Solar photocatalysis is one way to potentially generate cheap renewable fuels by harnessing energy from the sun and converting it into chemical energy. Photosensitizers serve as materials that absorb and store sunlight in the form of chemical energy. The efficiency of a photosensitizer depends on its capacity to form a prolonged triplet excited state. Zinc dipyrrin complexes have the potential to be efficient sensitizers for reductive photochemistry, but their ability to form long-lived triplet excited states still needs extensive research. The overall aim of this research is to probe the role charge separation plays in the formation of triplet state in metal complexes of dipyrrin photosensitizers. The specific objectives are to synthesize and characterize zinc and boron dipyrrin complexes, analyze their photophysical properties—such as steady-state spectroscopy, low-temperature emission spectroscopy—and quantify their triplet states using time-resolved transient absorption spectroscopy.