Articles de revues : « Group III metal complexes »

1

Pelmuş, Marius, Erik N. Carrión, Christopher Colomier, Jenyffer Santiago et Sergiu M. Gorun. « Group III perfluoroalkyl perfluoro phthalocyanines ». Journal of Porphyrins and Phthalocyanines 20, n^o 08n11 (août 2016) : 1401–8. http://dx.doi.org/10.1142/s1088424616501157.

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We report the synthesis, redox and photo-physical properties, as well as singlet oxygen reactivity of the first representatives of Group III perfluoroalkyl perfluoro metal phthalocyanines, gallium and indium complexes. Microwave-assisted synthesis was used to produce F[Formula: see text]PcM, M [Formula: see text] Ga, In in reasonable yields. Both Ga and In complexes exhibit high thermal and chemical stability properties, attributed to the perfluoroalkyl perfluoro phthalocyanine ligand. Electrochemical and spectroelectrochemical measurements show reversible redox processes for both compounds, including spontaneous re-oxidations following electrochemical or photochemical reductions. No electrochemical or chemical oxidations of the neutral complexes are observed. Photo-hydroperoxidation of ([Formula: see text]-(-)-citronellol occurs with rates of 13.5 and 1.7 [Formula: see text]mol O2 min[Formula: see text] mol[Formula: see text] Pc and substrate turnovers of 225 and 28.2 mmol ([Formula: see text]-Cit s[Formula: see text] mol[Formula: see text] Pc for the In and Ga complexes, respectively. The solid state materials are stable and can be sublimed at temperatures higher than 380°C. Related complexes are candidates for similar chemistry and photophysics based on the observation that the fluorinated ligand determines most of the favorable properties.

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Patel, Dipti, et Stephen T. Liddle. « f-Element-metal bond chemistry ». Reviews in Inorganic Chemistry 32, n^o 1 (1 juin 2012) : 1–22. http://dx.doi.org/10.1515/revic.2012.0001.

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AbstractCompared to the overwhelming prevalence of f-element-carbon, -nitrogen, -oxygen or -halide ligand linkages, the use of metal-based fragments as ligands is underdeveloped. This contrasts directly to the extensively developed fields of d- and p-block metal-metal complexes, which are still burgeoning. This review outlines the development of compounds that possess polarised covalent f-element-metal bonds. For this review, the f-element is defined as (i) a group 3 metal; (ii) a lanthanide metal; (iii) the actinide metals thorium or uranium. The metal is defined as: (i) a d-block transition metal; (ii) a group 13 metal (aluminium or gallium); (iii) a group 14 metal (silicon, germanium or tin); (iv) a group 15 metal (antimony or bismuth) metal. Although silicon, germanium and antimony are traditionally classified as metalloids, they are included for completeness. We focus on complexes that have been structurally authenticated by single crystal X-ray diffraction, and we highlight novel aspects of their syntheses, properties and reactivities.

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Wang, Bei-Bei, Huiping Zuo, John Mack, Poulomi Majumdar, Tebello Nyokong, Kin Shing Chan et Zhen Shen. « Optical properties and electronic structures of axially-ligated group 9 porphyrins ». Journal of Porphyrins and Phthalocyanines 19, n^o 08 (août 2015) : 973–82. http://dx.doi.org/10.1142/s108842461550073x.

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A series of group 9 metal tetra-(p-tolyl)-porphyrin ( M(ttp) , M = Co(II) , Rh(III) , Ir(III)) complexes with axial phenyl substituents have been synthesized and characterized. An aryl bromide cleavage reaction of transition metal complexes was used to prepare the complexes from Co(ttp) , Rh(ttp) Cl and Ir(ttp)COCl , respectively. Magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations have been used to study trends in the optical spectra and electronic structures. The effect of introducing different para-substituents on the phenyl substituents was examined. During fluorescence emission studies, phosphorescence was observed for the Ir(III) complexes in the near infrared (NIR) region.

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Pysarevska, Solomiya, Liliya Dubenska, Ivan Spanik, Jaroslav Kovalyshyn et Sofia Tvorynska. « Reactions of o,o′-Dihydroxy Azo Dyes with the Third Group M(III) Ions : A Spectroscopic and Electrochemical Study ». Journal of Chemistry 2013 (2013) : 1–10. http://dx.doi.org/10.1155/2013/853763.

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The reactions of some metal ions of the third group (M(III)) with azo dyes were studied. Attention was focused on azo dyes with two hydroxy groups inortho-positions to azo group: eriochrome red B (ERB), eriochrome black T (EBT), eriochrome blue SE (EBSE), calcon (Calc), and kalces (KLC). The chelation is responsible for interaction of these dyes with Al(III), Sc(III), rare earth elements (REE) ions, Ga(III), and In(III). The complexes were studied using vis- and IR-spectrometry. One irreversible peak (P1) of complexes reduction was observed on voltammograms for all studied metal ions. The second peak P2 was observed only for Ga complexes with all investigated azo dyes. Based on the study, the possible mechanism of complexes reduction was proposed. Linear behavior has been found between the reduction peak currents of a set of metal complexes and the concentration of the respective metal cations. This can be used for metal ions determination by voltammetric methods.

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Halder, Kalpataru, et Utpal Saha. « Synthesis and Evaluation of Cr (III), Mn (III) and Fe (III) Schiff Base of Metals Complexes ». Journal of Drug Delivery and Therapeutics 9, n^o 3 (15 mai 2019) : 114–16. http://dx.doi.org/10.22270/jddt.v9i3.2609.

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A novel synthesized Schiff base metal complexes Cr (III), Mn (III) and Fe (III) of 2-hydroxy-5-chloro acetophenone 2-imino-4-phenyl thiazole were prepared by condensed from 2-hydroxy-5-chloro acetophenone and 2-amino-4-phenyl thiazole have been synthesized and characterized on the basis of elemental analysis, Infrared, 1H NMR, molar conductance and magnetic susceptibilities analysis. The Schiff base acts as a monobasic bidentate ligand commonly coordinates through the oxygen atom of phenolic OH group and the nitrogen atom of azomethine group, which is confirmed by IR spectral data. All the metal complexes have studies thermal properties and their thermal parameter. Keyword: Schiff base, Magnetic, Thermal studies.

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Oldenburg, Karin, et Arnd Vogler. « Electronic Spectra and Photochemistry of Tin(II), Lead(II), Antimony(III), and Bismuth(III) Bromide Complexes in Solution ». Zeitschrift für Naturforschung B 48, n^o 11 (1 novembre 1993) : 1519–23. http://dx.doi.org/10.1515/znb-1993-1109.

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The electronic spectra of bromo complexes of main group metal ions with an s2 electronic configuration (SnBr3-, PbBr3-, PbBr42-, SbBr4-, SbBr63-, BiBr4-, BiBr63-) in acetonitrile show long-wavelength absorption bands which are assigned to metal-centered sp transitions. Compared to the corresponding chloro complexes the sp bands of the bromo complexes appear at longer wavelength due to sp/LMCT mixing (LMCT = ligand-to-metal charge transfer). As a result of this mixing the luminescence which originates from low-energy sp excited states is much weaker than that of the chloro complexes. Moreover, some of the bromo complexes (e.g. BiBr4-) undergo a photochemical redox decomposition induced by LMCT excitation.

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Zhang, Zaihui, T. L. Thomas Hui et Chris Orvig. « One-pot synthesis of N-substituted-3-hydroxy-4-pyridinone chelate complexes of aluminum, gallium, and indium ». Canadian Journal of Chemistry 67, n^o 11 (1 novembre 1989) : 1708–10. http://dx.doi.org/10.1139/v89-263.

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A series of tris(3-hydroxy-2-methyl-4-pyridinonato)metal(III) and tris(3-hydroxy-6-hydroxymethyl-4-pyridinonato)metal(III) complexes have been prepared in water by one-pot synthesis directly from maltol and kojic acid, respectively, and the metal ion (M = Al, Ga, In) with an appropriate amine. The pyridinones have substituents at the ring nitrogen atom (CH3, C2H5). The tris(3-hydroxy-4-pyronato)metal(III) complexes are formed insitu and these undergo nucleophilic attack by the primary amine; the appropriate tris(3-hydroxy-4-pyridinonato)metal(III) complexes are obtained. This method bypasses the sequential syntheses of ligand and metal complex, and has improved the yields of the tris(ligand)metal complexes, in particular by making them much more easily accessible. The electronic effects of binding the pyrone to the metal ions and of the substituents on the pyrone ring on the reactivity are discussed. Keywords: 3-hydroxy-4 pyridinone complexes, group 13 metal ions, one-pot synthesis.

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Mansoor Ahmed Zi Ning Lei, Mansoor Ahmed Zi Ning Lei, Mohsin Ali Mohsin Ali, Syed Imran Ali Syed Imran Ali, Konatsu Kojima Konatsu Kojima, Pranav Gupta Pranav Gupta, Majid Mumtaz Majid Mumtaz, Dong Hua Yang Dong Hua Yang et Syed Moazzam Haider and Zhe Sheng Chen Syed Moazzam Haider and Zhe Sheng Chen. « Synthesis, Characterization and Anticancer Activity of Isonicotinylhydrazide Metal Complexes ». Journal of the chemical society of pakistan 41, n^o 1 (2019) : 113. http://dx.doi.org/10.52568/000706/jcsp/41.01.2019.

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This study focuses characterization of iron (II), iron (III), cobalt (II), copper (II) and nickel (II) complexes of Isoniazid (INH) and studying their spectroscopic as well as physiochemical properties. FTIR studies showed that INH binds the metal from oxygen of carbonyl group and nitrogen of amino group. The proton NMR spectra of the metal complexes confirmed the conversion of ligand molecules into their respective metal complexes. However, pattern of splitting and shapes of peaks was observed but the protons resonated in the expected region. XRD patterns may be concluded that the complexes are mostly comprised of nano-sized particles behaving like amorphous materials. Scanning electron microscopy (SEM) revealed marked changes in the morphology of complexes, and their degradation at higher temperature strengthens the hypothesis of the successful formation of complexes. The MTT cytotoxicity assay was used for the screening these complexes against four human cell lines but the results did not prove significant.

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Tchertanov, L., et C. Pascard. « Statistical Analysis of Noncovalent Interactions of Anion Groups in Crystal Structures. III. Metal Complexes of Thiocyanate and their Hydrogen-Donor Accepting Function ». Acta Crystallographica Section B Structural Science 53, n^o 6 (1 décembre 1997) : 904–15. http://dx.doi.org/10.1107/s0108768197008549.

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The bidentate function of the thiocyanate anion was studied using the Cambridge Structural Database System. Complexing properties (metal–thiocyanate interactions) with respect to metal cations were analysed. Two main classes were distinguished: (a) alkali and alkaline earth metals, and (b) metals of Zn and Cu groups and transition metals (group VIII). Good correlations were found between the nature of the metal (radius, oxidation state and charge) and its position relative to the thiocyanate unit. Hydrogen-bond acceptor properties of discrete and complexed SCN units were compared. The extraordinarily active hydrogen-bonding behaviour allows this anion to act as a powerful bridge between different molecular fragments. In metal complexes the cation provokes a redistribution of anionic charge in SCN and the distribution of electron density, in turn, controls the hydrogen-bonding properties of the terminal acceptor atom. Binding properties of thiocyanate in biological systems were illustrated using the Brookhaven Protein Data Bank. A comparison of anion binding in small-molecule structures and in macromolecular structures shows good agreement.

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D'Elia, Valerio, Jérémie D. A. Pelletier et Jean-Marie Basset. « Cycloadditions to Epoxides Catalyzed by Group III-V Transition-Metal Complexes ». ChemCatChem 7, n^o 13 (25 mai 2015) : 1906–17. http://dx.doi.org/10.1002/cctc.201500231.

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Cherkasova, Tatyana G., et Elizaveta V. Cherkasova. « Crystal Structures of Binuclear Coordination Rare-Earth Metal Compounds ». Key Engineering Materials 670 (octobre 2015) : 9–14. http://dx.doi.org/10.4028/www.scientific.net/kem.670.9.

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The double complex compounds - hexa (isothiocyanate) chromates (III) of lanthanide (III) complexes with ε-caprolactam and nicotinic acid [Ln (ε-C6H11NO)8][Cr (NCS)6] and [Ln (C5H5NCOO)3(H2O)2][Cr (NCS)6]·nH2O, n=1,2 - were produced from the aqueous solutions by means of direct synthesis. The substances are studied by the spectroscopic method; their crystal structure is determined. It is found that all the complexes are of island ionic type. ε-C6H11NO complexes form triclinic system crystals - space group P ̄1, or monoclinic - space group С2/с. The nicotinic acid compositions crystallize in the monoclinic system, space group P21/n. The complexes have reversible heat-sensitive properties and can serve as the chemical sensors in the temperature-sensitive devices that are used for visual inspection of the thermal regime in various technological processes.

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Aguado, Javier E., M. Concepción Gimeno, Peter G. Jones et Antonio Laguna. « Unusual coordination behaviour of the ferrocenyl-terpyridine ligand with group 11 complexes ». Canadian Journal of Chemistry 87, n^o 1 (1 janvier 2009) : 341–47. http://dx.doi.org/10.1139/v08-148.

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Complexes of the ligand Fcterpy (Fcterpy = 4′-ferrocenyl-2,2′:6′,2′-terpyridine) with group 11 metals display different coordination modes. The reaction with complexes [Cu(NO3)(PPh3)2] or [M(OTf)(PR3)] (OTf = trifluoromethyl sulphonate) gives the species [M(Fcterpy)(PR3)]X (M = Cu, X = PF6, PR3 = PPh3 (1); M = Ag, X = OTf, PR3 = PPh3 (2), PPh2Me (3); M = Au, X = OTf, PR3 = PPh3 (4)) in which the ligand is coordinated as a tridentate chelate to the metal. Treatment with [Cu(NCMe)4]PF6 or Ag(OTf) in 1:1 molar ratio gives the dinuclear complexes [M2(Fcterpy)2]X2 (M = Cu (5), Ag (6)), in which the ligand is tetradentate because the central pyridine group is bonded to two metals. The reaction with the gold(I) complex [Au(C6F5)(tht)] (tht = tetrahydrothiophene) leads to the first example of a terpyridine ligand bonded to three metal atoms, [Au3(C6F5)3(Fcterpy)] (7); in the product of the corresponding reaction with the gold(III) derivative [Au(C6F5)3(OEt2)] to give [Au(C6F5)3(Fcterpy)] (8), the ligand is monodentate, which is also unusual for a terpyridine ligand.Key words: copper, silver, gold, terpyridine, ferrocene derivatives

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Schreiber, A., H. Rauter, M. Krumm, S. Menzer, E. C. Hillgeris et B. Lippert. « Multinuclear Metal Nucleobase Complexes ». Metal-Based Drugs 1, n^o 2-3 (1 janvier 1994) : 241–46. http://dx.doi.org/10.1155/mbd.1994.241.

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Of all properties of metal nucleobase complexes, formation of multinuclear species appears to be an outstanding feature. After a brief introduction into well known polymeric metal nucleobase complexes, three aspects recently Studied in our laboratory will be dealt with in more detail: (i) Heteronuclear complexes derived from trans-[(amine)2Pt(1-MeC)2]2+ (1-MeC=1-methylcytosine). They form, e. g. with Pd(II) or Hg(II), upon single deprotonation of the exocyclic amino group of each 1-MeC ligand, compounds of type trans-[(amine)2Pt(1-MeC-)2MY]n+, displaying Pt-M bond formation. (ii) Cyclic nucleobase complexes derived from cis-a2Pt(II). A cyclic compound of composition {[(en)Pt(UH-N1,N3)]4}4+ (UH=monoanion of unsubstituted uracil) is presented and the analogy with organic calix-[4]-arenes is pointed out. (iii) Cyclic nucleobase complexes from trans-a2Pt(II). Possible ways for the preparation of macrocyclic nucleobase complexes containing trans-a2Pt(II) linkages are outlined and precursors and intermediates are presented.

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Kovács, Attila, Christos Apostolidis et Olaf Walter. « Comparative Study of Complexes of Rare Earths and Actinides with 2,6-Bis(1,2,4-triazin-3-yl)pyridine ». Inorganics 7, n^o 3 (26 février 2019) : 26. http://dx.doi.org/10.3390/inorganics7030026.

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Complexes of group III metals (rare earth and actinides) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (BTP) have been investigated by computational (DFT) and, in limited cases, by experimental (FT-IR, X-ray) techniques with the goal of determining the characteristics of metal–ligand interactions. The DFT calculations using the M062X exchange-correlation functional revealed that metal–ligand distances correlate with the ionic radii of the metals, in agreement with available X-ray diffraction results on the Sc, Y, La, U, and Pu complexes. A related blue-shift trend could be observed in seven characteristic bands in the IR spectra associated with metal–ligand vibrations. The computations uncovered considerable charge transfer interactions, particularly in the actinide complexes, as important covalent contributions to the metal–ligand bonding. The covalent character of the metal–ligand bonds decreases in the actinides, from U to Cm.

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Engelhardt, LM, PC Healy, BW Skelton et AH White. « Lewis-Base Adducts of Group 11 Metal(I) Compounds. L. Heterobimetallic Tris(dithiocarbamato)metal(III)/Copper(I) Iodide Adducts [Metal(III) = Cr, Rh] ». Australian Journal of Chemistry 42, n^o 6 (1989) : 885. http://dx.doi.org/10.1071/ch9890885.

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A variety of heterobimetallic adducts formed between tris(dithiocarbarnato)cobalt(lII) complexes and copper(1) halides have been recorded. In the present paper, reports of the synthesis and structure determinations of [Rh {S2CN(CH2)4}3]3Cul (1), [Cr(S2CNEt2)3]. [Cr(S2CNEt2)3] and [Cr{S2CN(CH2)4}3].3Cul.MeCN (3), similar to cobalt(llI) counterparts, suggest that, in principle, the previously described chemistry of the cobalt(III) systems may be extended to analogous systems for dithiocarbamates of any non-labile trivalent metal. The novel Cu3I3 ring of (3) is disordered between possible boat forms.

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Al-Thubaiti, Eman H., Samy M. El-Megharbel, Bander Albogami et Reham Z. Hamza. « Synthesis, Spectroscopic, Chemical Characterizations, Anticancer Capacities against HepG-2, Antibacterial and Antioxidant Activities of Cefotaxime Metal Complexes with Ca(II), Cr(III), Zn(II), Cu(II) and Se(IV) ». Antibiotics 11, n^o 7 (19 juillet 2022) : 967. http://dx.doi.org/10.3390/antibiotics11070967.

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In this study, metal cefotaxime complexes of Ca(II), Cr(III), Cu(II), Zn(II), and Se(VI) were synthesized and characterized by elemental analysis, conductance measurements, IR, electronic spectra, magnetic measurements, 1HNMR, and XRD, as well as by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The lower values for molar conductance refer to the nonelectrolyte nature of the complexes. The FTIR and 1H-NMR spectra for the metal complexes of cefotaxime proved that the free cefotaxime antibiotic ligand acted as a monoanionic tridentate ligand through the oxygen atoms of lactam carbonyl, the carboxylate group, and the nitrogen atoms of the amino group. From the magnetic measurements and electronic spectral data, octahedral structures were proposed for the Cr(III) and Se(VI) complexes, while the Cu(II) complex had tetragonal geometry. This study aimed to investigate the effects of cefotaxime and cefotaxime metal complexes on oxidative stress using antioxidant assays including DPPH, ORAC, FARAB, and ABTS, a metal chelation assay, as well as the inhibition of the viability of cancer cells (HepG-2). Regarding the antibacterial activity, the cefotaxime metal complexes were highly effective against both Bacillus subtilis and Escherichia coli. In conclusion, the cefotaxime metal complexes exhibited highly antioxidant activities. The cefotaxime metal complexes with Zn and Se inhibited HepG-2 cellular viability. Thus, the cefotaxime metal complexes elicited promising results as potent antioxidant and anticancer agents against HepG-2, with potent antibacterial activities at a much lower concentration.

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Doerrer, Linda H., Jennifer C. Green, Malcolm L. H. Green, Ionel Haiduc, Christian N. Jardine, Sofia I. Pascu, Luminita Silaghi-Dumitrescu et David J. Watkin. « Group 6 transition metal carbonyl complexes with chalcogen-bridged diarsenic(III) ligands ». Journal of the Chemical Society, Dalton Transactions, n^o 19 (2000) : 3347–55. http://dx.doi.org/10.1039/b005269h.

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Al-Farhan, Badriah Saad, Maram T. Basha, Laila H. Abdel Rahman, Ahmed M. M. El-Saghier, Doaa Abou El-Ezz, Adel A. Marzouk, Mohamed R. Shehata et Ehab M. Abdalla. « Synthesis, DFT Calculations, Antiproliferative, Bactericidal Activity and Molecular Docking of Novel Mixed-Ligand Salen/8-Hydroxyquinoline Metal Complexes ». Molecules 26, n^o 16 (4 août 2021) : 4725. http://dx.doi.org/10.3390/molecules26164725.

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Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2′-{1,2-ethanediylbis[nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR, 1H NMR, 13C NMR, UV–VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H2O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H2O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC50 values (1.49 and 1.95 µM, respectively) that were comparable to that of cisplatin (1.55 µM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC50 values of 1.95 and 1.43 µM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and -negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.

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Musa, Shuaibu, Suleiman Ola Idris, David A. Onu et Ahmed B. Suleiman. « Synthesis, Characterization, and Biological Evaluation of Chromium(III) Complexes of Alanine and Valine ». Avicenna Journal of Environmental Health Engineering 6, n^o 2 (31 décembre 2019) : 100–105. http://dx.doi.org/10.34172/ajehe.2019.13.

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Two metal-amino acid complexes, Cr(III)-alanine and Cr(III)-valine, were synthesized and characterized by IR spectroscopy, powder X-ray diffraction (XRD) analysis, magnetic susceptibility, and molar conductivity measurements. Molar conductivity measurements indicated that the composition of the metal complexes corresponds to a metal-amino acid ligand ratio of 1:3. The IR spectra indicated that the amino acids act as bidentate ligands with coordination involving the carboxyl oxygen and the nitrogen of the amino group. Magnetic susceptibility measurements revealed a six-coordinate local symmetry around the Cr(III) ions which depicted that the complexes were paramagnetic with magnetic moment values ranging from 5.10 to 6.00 BM. Powder XRD studies confirmed that the amino acid complexes were crystalline with monoclinic crystal structure. The in vitro biological activity of the investigated chromium(III) complexes with alanine and valine was tested against Bacillus subtilis, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, and Escherichia coli. All the microorganisms were standardized using 0.5 McFarland standard. The antimicrobial studies showed that the ligands were biologically active with an inhibition zone range of 10-17 mm and their metal complexes showed significantly enhanced antimicrobial sensitivity with an inhibition zone range of 12-21 mm. The standard drug showed slightly better activity with an inhibition zone range of 24-38 mm.

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Mishra, Manoj Kumar. « NUCLEAR MAGNETIC RESONANCE (1HNMR) STUDY OF CHROMIUM (III) SALICYLATE AND BENZOATE COMPLEXES ». Rasayan Journal of Chemistry 15, n^o 01 (2022) : 217–20. http://dx.doi.org/10.31788/rjc.2022.1516206.

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Chromium (III) salicylate and Chromium (III) benzoate complexes were prepared using Chromium trioxide and different molar concentrations of salicylic and benzoic acid. Tertiary amyl alcohol and ethanol are used as a solvent. 1HNMR spectra of solid samples were recorded. 1HNMR spectra of metal complexes suggest that deprotonation of – COOH group took place, and the complex formed was not through the –OH of the acid. It confirms the coordination of the ligand to the metal ion through the carboxylic oxygen atom.

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Ayeni, Ayowole O., et Gareth M. Watkins. « Impact of Thiocyanate on the Catecholase Activity of Cu(II) and Fe(III) Complexes of 2-((4-(2-Hydroxy-4-Methylbenzyl)Piperazin-1-YL)Methyl)-5-Methylphenol (A Mannich Base) ». Acta Chemica Iasi 26, n^o 1 (1 juillet 2018) : 59–73. http://dx.doi.org/10.2478/achi-2018-0005.

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Abstract Four metal complexes viz Cu(II) and Fe(III) with or without thiocyanate have been synthesized from a Mannich base prepared by a simple synthetic route. These complexes were characterized by elemental and spectroscopic techniques. Bonding modes of the thiocyanate group with the metal complexes as studied by infrared spectroscopy revealed the presence of bridging N- and S- bonding modes. Detailed kinetic studies of these complexes were carried in the evaluation of their catecholase activity. The Fe(III) complex demonstrated the highest catalytic activity using 3,5-di-tert-butyl catechol (3,5-DTBC) as substrate with a turnover rate (kcat) of 112.32 h−1.

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AL-HILFI, Jassim Abas, Zaidoon Jawad KAHDIM, Tahseen Saddam FANDI et Luma M. AHMED. « STRUCTURAL STUDY OF COMPLEXES FROM HEXAFLUOROACETYLACETONE, PYRAZOLE, AND ITS PYRAZOLE DERIVATIVE WITH SOME METALS BY FT-IR, AND 1H-NMR ». Periódico Tchê Química 17, n^o 34 (20 mars 2020) : 756–68. http://dx.doi.org/10.52571/ptq.v17.n34.2020.780_p34_pgs_756_768.pdf.

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The series complex formation nickel(II) or cobalt(III) with hexafluoroacetylacetone, pyrazole, 3,5-dimethylpyrazole, and 3,5-bis(trifluoromethyl)-1H-pyrazole were prepared. The first reaction step included the synthesis of the complex using hexafluoroacetylacetone as a ligand with Co(III) or Ni(II), metals with high spin with π donate and enol-form of the ligand. This formed complex was identified by FT-IR, 1H-NMR spectroscopy, and magnetic susceptibility calculation. Whereas, the second reaction step to produce the complex depended upon mixing water and pyrazole and using it as ligands with Co(III) or Ni(II) a metal, which is a high spin with one donate and the another is aromatic nitrogen atom in a ligand. In the third reaction step, the complexes were produced by mixing water with 3,5-bis(trifluoromethyl)-1H-pyrazole as a ligand with Co(III) or Ni(II) as low spin metal. The analysis of these prepared complexes and their used ligands were done by comparing the results using 1H-NMR and FT-IR spectroscopies. Besides, the magnetic susceptibility calculation was also employed. The results of 1H-NMR spectroscopy and magnetic susceptibility proved that the produced complexes are diamagnetic when the ligand includes the CF3 group. At the same time, the produced complexes are paramagnetic, when the ligand without the CF3 group, which is formed the mixture of water and 3,5-dimethylpyrazole as ligand or water and pyrazole as a ligand with Co(III) or Ni(II) as metal. All the ligands in the paramagnetic complexes were one donate, and another the donated atom in pyrazol is an aromatic nitrogen atom. Therefore all prepared high spin complexes were not evident in the 1H-NMR spectrum because the peaks appear brood that due to high T1 relaxation 1H-NMR time, and the investigation turned out two assignment peaks. This behavior is an attitude to happen the ketone form and enol form phenomenon by using 1H-NMR spectra, and its an evident assignment coupling between hydrogen or carbon atom with a fluorine atom.

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Eroshin, Alexey V., Arseniy A. Otlyotov, Ilya A. Kuzmin, Pavel A. Stuzhin et Yuriy A. Zhabanov. « DFT Study of the Molecular and Electronic Structure of Metal-Free Tetrabenzoporphyrin and Its Metal Complexes with Zn, Cd, Al, Ga, In ». International Journal of Molecular Sciences 23, n^o 2 (15 janvier 2022) : 939. http://dx.doi.org/10.3390/ijms23020939.

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The electronic and molecular structures of metal-free tetrabenzoporphyrin (H2TBP) and its complexes with zinc, cadmium, aluminum, gallium and indium were investigated by density functional theory (DFT) calculations with a def2-TZVP basis set. A geometrical structure of ZnTBP and CdTBP was found to possess D4h symmetry; AlClTBP, GaClTBP and InClTBP were non-planar complexes with C4v symmetry. The molecular structure of H2TBP belonged to the point symmetry group of D2h. According to the results of the natural bond orbital (NBO) analysis, the M-N bonds had a substantial ionic character in the cases of the Zn(II) and Cd(II) complexes, with a noticeably increased covalent contribution for Al(III), Ga(III) and In(III) complexes with an axial –Cl ligand. The lowest excited states were computed with the use of time-dependent density functional theory (TDDFT) calculations. The model electronic absorption spectra indicated a weak influence of the nature of the metal on the Q-band position.

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Shamsutdinova, Medina Humaidovna, Zara Sultanovna Ilkhaeva et Alet Ilyasovna Khasaeva. « SYNTHESIS, STRUCTURE AND PROPERTIES OF COMPLEX COMPOUNDS OF ANTHANOIDS WITH 4 - [(3,4-DIMETOXYBENZYL) AMINO] BENZOIC ACID ». EurasianUnionScientists 6, n^o 7(76) (20 août 2020) : 28–31. http://dx.doi.org/10.31618/esu.2413-9335.2020.6.76.940.

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The synthesis of complex compounds of 4 - [(3,4-dimethoxybenzyl) amino] benzoic acid (HL) with ions of samarium (III), europium (III), terbium (III), gadolinium (III) and dysprosium (III). According to the data of elemental analysis and thermogravimetry, the obtained complexes are hydrates of the composition LnL3 · nH2O, where n = 0-2. The area of their thermal stability is in the range from 100 ° С to 150 ° С. Electronic and infrared absorption spectra of the ligand and complexes with rare-earth metal ions have been measured. According to the IR spectra, the coordination of the ligand with the metal ion occurs at the carboxyl group. The carboxyl group is bidentate coordinated. To excite luminescence, a line of a mercury lamp with a wavelength of 248 nm was used. The highest luminescence intensity is observed for the coordination compounds Eu3 +, Tb3 +, Sm3 +, and Dy3 +.

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Shamsutdinova, M., et F. Dzhebirkhanova. « COMPLEX COMPOUNDS OF LANTANOIDS WITH 4 - [(2,4-DIMETOXYBENZYL) AMINO] BENZOIC ACID. » National Association of Scientists 2, n^o 68 (1 juillet 2021) : 57–60. http://dx.doi.org/10.31618/nas.2413-5291.2021.2.68.454.

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The synthesis of complex compounds of 4 - [(2,4-dimethoxybenzyl) amino] benzoic acid (HL) with ions of samarium (III), europium (III), terbium (III), gadolinium (III) and dysprosium (III). According to the data of elemental analysis and thermogravimetry, the obtained complexes are hydrates of the composition LnL3 · nH2O, where n = 0-2. The area of their thermal stability is in the range from 100 ° С to 150 ° С. Electronic and infrared absorption spectra of the ligand and complexes with rare-earth metal ions have been measured. According to the IR spectra, the coordination of the ligand with the metal ion occurs at the carboxyl group. The carboxyl group is bidentate coordinated. To excite luminescence, a line of a mercury lamp with a wavelength of 248 nm was used. The highest luminescence intensity is observed for the coordination compounds Eu3 +, Tb3 +, Sm3 +, and Dy3 +.

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Gatus, Mark R. D., Mohan Bhadbhade et Barbara A. Messerle. « Highly versatile heteroditopic ligand scaffolds for accommodating group 8, 9 & ; 11 heterobimetallic complexes ». Dalton Trans. 46, n^o 41 (2017) : 14406–19. http://dx.doi.org/10.1039/c7dt02854g.

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Two highly versatile xanthene scaffolds containing pairs of heteroditopic ligands were found to be capable of accommodating a range of transition metal ions, including Au(i), Ir(i), Ir(iii), Rh(i), and Ru(ii) to generate an array of heterobimetallic complexes.

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Kovacs, Michael S., Vishakha Monga, Brian O. Patrick et Chris Orvig. « Lanthanide(iii) and group 13 metal ion complexes of tripodal amino phosphinate ligands ». Dalton Trans., n^o 1 (2006) : 31–38. http://dx.doi.org/10.1039/b507905e.

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Driessen, W. L., L. M. van Geldrop et W. L. Groeneveld. « Complexes with ligands containing the nitro group : Part III. Metal(II) nitrobenzene solvates ». Recueil des Travaux Chimiques des Pays-Bas 89, n^o 12 (2 septembre 2010) : 1271–75. http://dx.doi.org/10.1002/recl.19700891207.

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D'Elia, Valerio, Jeremie D. A. Pelletier et Jean-Marie Basset. « ChemInform Abstract : Cycloadditions to Epoxides Catalyzed by Group III-V Transition-Metal Complexes ». ChemInform 46, n^o 34 (août 2015) : no. http://dx.doi.org/10.1002/chin.201534282.

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Su, Cheng-Yong, Bei-Sheng Kang, Xiao-Qin Mu, Jie Sun, Ye-Xiang Tong et Zhong-Ning Chen. « Studies on Lanthanide Complexes of the Tripodal Ligand Tris(benzimidazol-2-ylmethyl)amine (ntb). Crystal Structures of [Ln(ntb)(NO3)3].H2O (Ln = Ce, Er) ». Australian Journal of Chemistry 51, n^o 7 (1998) : 565. http://dx.doi.org/10.1071/c97014.

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The tripodal ligand tris(benzimidazol-2-ylmethyl)amine (ntb) reacts with lanthanide nitrates in methanol to give the mononuclear complexes [Ln(ntb)(NO3)3].H2O (Ln = La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er) which have been characterized by elemental analyses, infrared, electronic and 1H n.m.r. spectroscopies, X-ray diffraction patterns, and conductivity measurements. The crystal and molecular structures of two complexes [Ln(ntb)(NO3)3].H2O (Ln = Ce, Er) have been determined. The cerium complex crystallizes in the monoclinic system, space group C2/c with a 26·79(1), b 14·497(8), c 17·20(1) Å, β 99·06(4)°, V 6596(6) Å3 , Z 8, while the erbium complex crystallizes in the cubic system, space group Pa-3 with a 18·2504(1) Å, V 6078·79(6) Å3, Z 8. In both cases the central metal ions are coordinated to the four nitrogen atoms of ntb and six oxygen atoms of three chelating nitrate groups. The total coordination number of the metal ion is 10. Spectroscopic analyses suggest that other complexes show a similar coordination mode. The fluorescence properties of the samarium(III), europium(III), terbium(III), and dysprosium(III) complexes were investigated.

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Gwaram, N. S., A. Salisu et Muhammad Manir. « GREEN SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES OF MIXED LIGAND COMPLEXES OF Co (II), Ni (II) and V(III) METALS USING SOME AMINO ACIDS AS LIGANDS ». FUDMA JOURNAL OF SCIENCES 4, n^o 4 (12 juin 2021) : 191–99. http://dx.doi.org/10.33003/fjs-2020-0404-471.

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Co (II), Ni (II) and V (III) metal complexes were synthesized mechanochemically using L-Leucine, L-Tyrosine and Creatinine as mixed ligands. The metals and the ligands were grounded using an agate mortar with a pestle. The compounds formed were characterized using their melting/decomposition temperature, solubility, magnetic susceptibility, conductivity measurement, Infrared analysis and scanning electron microscope (SEM). The Metal – ligand ratios were investigated via Job’s method of continuous variation. The shifts of bands (for instance 1693-1677 cm-1 to 1674-1607 cm-1) in C=O and the appearance of new bands in the complexes (683-669 and 713-750 cm-1 indicates the complexation. The lower conductivity measurement values (15.00 to 32.40) µS.cm-1 suggested the non-electrolytic nature of the complexes. The magnetic effective value of the metal complexes showed that all the three complexes are paramagnetic and octahedral. It was concluded that the amino acids (ligands) coordinated in a bidentate way through the nitrogen from the amino group and oxygen from carboxylate. The complexes were screened for their antimicrobial activities against two bacterial isolates (Streptococcus pneumoniae and Klebsiella pneumoniae). All the complexes exhibited good activity against the organisms

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Matano, Yoshihiro, Takashi Nakabuchi et Hiroshi Imahori. « Synthesis, structures, and aromaticity of phosphole-containing porphyrins and their metal complexes ». Pure and Applied Chemistry 82, n^o 3 (14 février 2010) : 583–93. http://dx.doi.org/10.1351/pac-con-09-08-05.

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Our recent studies on the synthesis, structures, and aromaticity of phosphole-containing porphyrins and their metal complexes are summarized. Core-modified P,X,N2-porphyrins (X = S, N) are accessible from a σ4-phosphatripyrrane and the corresponding 2,5-difunctionalized heteroles in a few steps. X-ray structural analysis of the σ3-P,N3 porphyrin revealed that it possesses a slightly distorted 18π plane. The phosphorus atom incorporated at the core plays an important role in producing unprecedented reactivity and coordinating ability for the porphyrin ring. The P,N3 free base reacts with [RhCl(CO)2]2 in dichloromethane, ultimately yielding an 18π P,N3–rhodium(III) complex, whereas the P,S,N2 free base undergoes redox-coupled complexation with zero valent group 10 metals to afford the corresponding P,S,N2-isophlorin–metal(II) complexes. The aromaticity of the free-base porphyrins and the metal complexes was uncovered based on both experimental and theoretical results. It is of particular interest that the P,S,N2-isophlorin–metal complexes exhibit only a weak antiaromaticity in terms of the magnetic criterion.

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Canales, Silvia, Olga Crespo, M. Concepcíon Gimeno, Peter G. Jones et Antonio Laguna. « Group 11 Complexes with the Bidentate (SePPh2)2CH2 and Tridentate [(SePPh2)2CH]– Ligands ». Zeitschrift für Naturforschung B 62, n^o 3 (1 mars 2007) : 407–12. http://dx.doi.org/10.1515/znb-2007-0314.

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The reaction of (SePPh2)2CH2 with group 11 metal complexes such as [Au(C6F5)3(tht)] (tht = tetrahydrothiophene) affords the complex [Au(C6F5)3(SePPh2CH2PPh2Se)] in which the ligand coordinates to the gold(III) center only through one selenium atom. The treatment of the ligand with Ag(OTf) or [Cu(NCMe)4]PF6 leads, depending on the molar ratio, to the complexes [Ag2{(SePPh2)2CH2}2](OTf)2 or [M{(SePPh2)2CH2}2]X (M = Ag, X = OTf; M = Cu, X = PF6; OTf = CF3SO3) in which the phosphine selenide ligand coordinates as a bidentate bridging or chelating ligand through the Se,Se atoms. The reaction of (SePPh2)2CH2 with [Au(C6F5)2(acac)] (acac = acetylacetonate) occurs with deprotonation of the methylene group, and the methanide complex, [Au(C6F5)2(SePPh2CHPPh2Se)], is obtained, with a bidentate chelate Se,C coordination to the gold(III) center. The selenium atom can react further with other metal complexes such as [Au(C6F5)3(tht)] to give the dinuclear species [Au(C6F5)2{SePPh2CHPPh2SeAu(C6F5)3}], in which the ligand coordinates in a tridentate Se,C,Se form. The crystal structure of [Au(C6F5)2{SePPh2CHPPh2SeAu(C6F5)3}] has been established by X-ray diffraction.

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Dawara, Latika, S. C. Joshi et R. V. Singh. « Synthesis, Characterization, and Antimicrobial and Antispermatogenic Activity of Bismuth(III) and Arsenic(III) Derivatives of Biologically Potent Nitrogen and Sulfur Donor Ligands ». International Journal of Inorganic Chemistry 2012 (22 avril 2012) : 1–9. http://dx.doi.org/10.1155/2012/372141.

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A series of Bi(III) and As(III) complexes with two N∩S donor ligands, 1-(4-chloro-2-oxo-2H-chromen-3-yl)-methylene)-thiosemicarbazide (L1H) and N′-[1-(2-oxo-2H-chrome-3yl-ethylidene]-hydrazinecarbodithionic acid benzyl ester (L2H) have been synthesized by the reaction of BiCl3 and Ph3As with ligands in 1 : 1 and 1 : 2 molar ratios. All the synthesized compounds were characterized by elemental analyses, melting point determinations, and a combination of electronic, IR, 1H NMR, 13C NMR spectroscopic techniques, and X-ray diffraction for structure elucidation. In order to evaluate the effect of metal ions upon chelation, both the ligands and their complexes have been screened for their antimicrobial activity against the various pathogenic bacterial and fungal strains. The metal complexes have shown to be more antimicrobial against the microbial species as compared to free ligands. Both the ligands and their corresponding metal complexes have been tested for their antifertility activity in male albino rats. The marked reduction in sperm motility and density resulted in infertility. Significant alterations were found in biochemical parameters of reproductive organs in treated animals as compared to control group. It is concluded that all these effects may finally impair the fertility of male rats.

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Mansour, Ahmed M., et Krzysztof Radacki. « Antimicrobial properties of half-sandwich Ir(iii) cyclopentadienyl complexes with pyridylbenzimidazole ligands ». Dalton Transactions 49, n^o 14 (2020) : 4491–501. http://dx.doi.org/10.1039/d0dt00451k.

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Ethyl group determined the toxicity of pyridylbenzimidazole Ir(iii) compounds and exchange of the group with sulfonate led to diminishing of the antibacterial activity. Increasing the metal content per complex, 3, gave rise to a compound with no toxicity.

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Gallicano, Keith D., et Norman L. Paddock. « Cyclotetraphosph(III)azanes : donor properties and ylide formation ». Canadian Journal of Chemistry 63, n^o 2 (1 février 1985) : 314–18. http://dx.doi.org/10.1139/v85-052.

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The ligand (MeNPMe)4 (L) forms complexes [Formula: see text] [Formula: see text] L.M(CO)3 (M = Cr, Mo, W, Mn+), and a nickel complex L.Ni2(CO)3, which is easily oxidised to the phosphonimide [MeNP(0)Me]4. Quaternary complexes [LM(CO)3R]+I− have been prepared both by quaternisation of the neutral complex (R = Me, CH2CN, CH2C(O)NH2, M = Cr, Mo, W) and (R = Me) by reaction of the simple quaternary with the metal carbonyl. The quaternary complexes have been deprotonated to ylidic complexes, L.M(CO)3CH2 (M = Mo, W) in which the ylidic group has displaced one phosphine function. Chemical and structural features are discussed in terms of d-orbital contraction by acceptor groups. The phosphazane (MeNPPh)4 has been prepared.

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Makarenko, Alexander M., Dzmitry H. Zaitsau et Kseniya V. Zherikova. « Metal-Organic Chemical Vapor Deposition Precursors : Diagnostic Check for Volatilization Thermodynamics of Scandium(III) β-Diketonates ». Coatings 13, n^o 3 (1 mars 2023) : 535. http://dx.doi.org/10.3390/coatings13030535.

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Scandium complexes with β-diketonate ligands are valuable precursors for the metal–organic chemical vapor deposition (MOCVD) of scandia based materials, but data on their volatilization thermodynamics crucial to MOCVD technology are in a huge disarray. We have addressed this issue with a diagnostic tool based on the principles of group additivity and structure–property relationships, which had been developed by us specifically for metal–organic objects. For this purpose, a mass of experimental data on the vapor pressures and enthalpies of sublimation, vaporization and fusion available in the literature for scandium(III) β-diketonates has been compiled and analyzed. Additionally, saturated vapor pressures and thermodynamic sublimation characteristics have been obtained for scandium(III) complexes with acetylacetone, hexafluoroacetylacetone, and 3-methyl-2,4-pentanedione by transpiration and thermogravimetric methods. New data have allowed us to arbitrate the conflict of literature data. As a result, a consistent set of enthalpies of the three discussed processes has been obtained for eight scandium complexes. Dispersion interactions and non-additive effects have been shown to be typical for metal tris-β-diketonates. They have been taken into account to improve the diagnostic check. It is now possible to quite easily assess the thermodynamics of tris-β-diketonate complexes with different metals which are in demand as precursors in gas-phase technology.

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Matsuba, Carey A., Steven J. Rettig et Chris Orvig. « Main group (IIIA or 13) complexes of benzohydroxamic acid and the crystal structure of tris(benzohydroxamato)indium(III) ». Canadian Journal of Chemistry 66, n^o 8 (1 août 1988) : 1809–13. http://dx.doi.org/10.1139/v88-292.

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A series of tris(benzohydroxamato)metal(III) complexes has been prepared and characterized wherein the metals are aluminum, gallium, and indium. The complexes are synthesized in high yield from aqueous solution. The indium complex, as its ethanol solvate In(C7H6NO2)3•C2H5OH, has been studied by single crystal X-ray diffraction. The crystals are monoclinic with a = 11.091(2), b = 18.065(3), c = 12.861(2) Å, β = 105.55(1)°, Z = 4, and space group P21/n. The structure was solved by Patterson and Fourier methods and was refined by full-matrix least-squares procedures to R = 0.038 and Rw = 0.037 for 2579 reflections with I ≥ 3σ(I). Bond lengths and angles in the compound were normal, although there is a strong In—O(C) interaction; the arrangement of the three ligands is mer. There is extensive hydrogen bonding involving all possible donors. All three complexes have been studied by mass spectrometry, and by infrared and nuclear magnetic resonance (1H, 27Al) spectroscopies. Parallel studies have been attempted with acetohydroxamic acid.

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Malesev, Dusan, et Vesna Kuntic. « Investigation of metal-flavonoid chelates and the determination of flavonoids via metal-flavonoid complexing reactions ». Journal of the Serbian Chemical Society 72, n^o 10 (2007) : 921–39. http://dx.doi.org/10.2298/jsc0710921m.

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Flavonoids constitute a large group of polyphenolic phytochemicals with antioxidant properties which are overwhelmingly exerted through direct free radical scavenging. Flavonoids also exhibit antioxidant properties through chelating with transition metals, primarily Fe(II), Fe(III) and Cu(II), which participate in reactions generating free radicals. Metal-flavonoid chelates are considerably more potent free radical scavengers than the parent flavonoids and play a prominent role in protecting from oxidative stress. To unravel the origin of their potent biological action extensive physico-chemical studies were undertaken to reveal the chemical structure, chelation sites, assess the impact of the metal/ligand ratio on the structure of the complexes and the capacity of flavonoids to bind metal ions. In spite of such extensive efforts, data on the composition, structure and complex-formation properties are incomplete and sometimes even contradictory. The aim of this paper is to give a personal account on the development of the field through a retrospective evaluation of our own research which covers approximately 40 complexes of flavonoids from different flavonoids subclasses (rutin, quercetin, 3-hydroxyflavone, morin and hesperidin) with several metal ions or groups and suggest directions for future research. Special emphasis will be given to the site of the central ion, the composition of the complexes, the role of pH in complex formation, the stability of metal-flavonoid complexes and their potential application for analytical purposes. .

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KAKARLA, Ramana Kumar, Raghavendra Guru Prasad ALURU, Srilalitha VINNAKOTA et RAO KRISHNA RAO, Ravindranath LAKSHMANA. « SYNTHESIS AND CHARACTERIZATION OF MALONIC ACID DIHYDRAZIDE AND ITS METAL COMPLEXES ». Periódico Tchê Química 12, n^o 24 (20 janvier 2013) : 26–33. http://dx.doi.org/10.52571/ptq.v11.n20-21.2013.26_periodico20e21_pgs_26_33.pdf.

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A new series of complexes was synthesized by the reaction between malonyl dihydrazide (MAH) and manganese, copper, nickel, zinc, cadmium, cobalt and ferric salts in methanolic medium. The complexes were characterized by elemental analysis, molar conductance measurements, electronic, IR and 1H NMR spectral studies. Based on the results obtained, the stoichiometry of Fe(III)-MAH and Co(III)-MAH was proposed to be 1:3 and that for Cu(II)-MAH, Cd(II)-MAH, Zn(II)-MAH, Mn(II)-MAH, Ni(II)-MAH was proposed to be 1:2 (M:L). It was suggested that the nitrogen present in the azomethine (>C=N-) group of the enolic form present in the ligand was involved in the formation of complexes. A clear picturisation indicating the bonding sites were depicted for each complex. The metal complexes exhibit different geometries such as tetrahedral, square planar and octahedral arrangements.

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Shamsutdinova, M. H., N. R. Tashligov et L. E. Ilyasova. « SYNTHESIS, STRUCTUREAND PROPERTIES OF COMPLEX COMPOUNDS OF LANTANOIDES WITH 2-(METHYLAMINO) BENZOIC ACID ». National Association of Scientists 3, n^o 28(55) (15 juin 2020) : 46–49. http://dx.doi.org/10.31618/nas.2413-5291.2020.3.55.224.

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Synthesis of complex compounds of 2-(methylamino) benzoic acid (L) with ions of samarium (III), europium (III), terbium (III), gadolinium (III) and dysprosium (III). According to elemental analysis and thermogravimetry, the complexes obtained are hydrates of the composition LnL3 • nH2O, where n = 1-5. The area of their thermal stability ranges from 100 ° C to 240 ° C. Electronic and infrared absorptionspectra of the ligand and complexeswith rare-earth metal ions were measured. According to the IR spectra, coordination of the ligand with the metal ion is carried out on the carboxyl group. The carboxyl group is coordinated bidentately. A mercury lampwith a wavelength of 248 nm was used to excite the luminescence. The highest luminescence intensity is observed for the coordination compounds Eu3 +, Tb3 +, and Dy3 +

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Junk, Peter C., Brian W. Skelton et Allan H. White. « Structural Characterization of Some Complexes of Group 13 Metal(III) Nitrates with N,N′-Bidentate Bases ». Australian Journal of Chemistry 59, n^o 2 (2006) : 147. http://dx.doi.org/10.1071/ch05267.

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The structural characterization of several novel complexes of gallium(iii) and indium(iii) nitrates, crystallized with 2,2′-bipyridyl (bpy) and 1,10-phenanthroline (phen) from nitromethane solution, is presented. The adduct In(NO3)3:bpy (1:2) is of the form [(ONO2)(O2NO)2In(bpy)2], rather than [(ONO2)3ML2] as found for the larger M = Ln (rare earth), Bi, despite similar 2-symmetry. Several hydroxo-bridged dimers, [L2M(OH)2ML2](NO3)4(·S) are also presented, the cations all of the same isomeric form. [(ONO2)(bpy)In(OH)2In(bpy)(O2NO)], interestingly, displays two different forms within the one crystal, by virtue of different dispositions of the coordinated nitrate. The structures of related cis-[(phen)2GaBr2]Br(·S) and [(en)2In(OH)2In(en)2](NO3)4 (en = H2N(CH2)2NH2) are also described, the latter isomorphous with its cobalt(iii) counterpart.

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Kalinowska, Monika, Kamila Gryko, Ewelina Gołębiewska, Grzegorz Świderski, Hanna Lewandowska, Marek Pruszyński, Małgorzata Zawadzka, Maciej Kozłowski, Justyna Sienkiewicz-Gromiuk et Włodzimierz Lewandowski. « Fe(III) and Cu(II) Complexes of Chlorogenic Acid : Spectroscopic, Thermal, Anti-/Pro-Oxidant, and Cytotoxic Studies ». Materials 15, n^o 19 (1 octobre 2022) : 6832. http://dx.doi.org/10.3390/ma15196832.

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Complexes of chlorogenic acid (5-CQA) with copper(II) and iron(III) were synthesized in a solid state and examined by means of FT-IR, thermogravimetric, and elemental analyses. The molar stoichiometric ratios of metal:ligand for the solid forms of the complexes were established as Cu(II):L = 1:2 and Fe(III):L = 2:3 (L: 5-CQA), with the possible coordination through the carboxylate group and the hydroxyl group from the catechol moiety. In an aqueous solution at pH = 7.4, the composition of the complexes was Cu(II):L = 1:1, and Fe(III):L = 1:1 and 1:2. The Cu(II) and Fe(III) complexes with 5-CQA showed lower antioxidant properties, as estimated by the spectrophotometric methods with DPPH•, ABTS•+, and HO• radicals, than the ligand alone, whereas in the lipid peroxidation inhibition assay, the metal complexes revealed a higher antioxidant activity than 5-CQA. Cu(II) 5-CQA showed the highest pro-oxidant activity in the Trolox oxidation assays compared to the other studied compounds. The lipophilic parameters of the compounds were estimated using the HPLC method. 5-CQA and its complexes with Fe(III) and Cu(II) were not toxic to HaCaT cells in a tested concentration range of 0.15–1000 nM after a 24 h incubation time.

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Elshafie, Hazem S., Sadeek A. Sadeek, Ippolito Camele et Amira A. Mohamed. « Biochemical Characterization of New Gemifloxacin Schiff Base (GMFX-o-phdn) Metal Complexes and Evaluation of Their Antimicrobial Activity against Some Phyto- or Human Pathogens ». International Journal of Molecular Sciences 23, n^o 4 (14 février 2022) : 2110. http://dx.doi.org/10.3390/ijms23042110.

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Four novel ligand-metal complexes were synthesized through the reaction of Fe(III), pleaseCo(II), Zn(II), and Zr(IV) with Schiff base gemifloxacin reacted with ortho-phenylenediamine (GMFX-o-phdn) to investigate their biological activities. Elemental analysis, FT-IR, 1H NMR, UV-visible, molar conductance, melting points, magnetic susceptibility, and thermal analyses have been carried out for insuring the chelation process. The antimicrobial activity was carried out against Monilinia fructicola, Aspergillus flavus, Penicillium italicum, Botrytis cinerea, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, and P. aeruginosa. The radical scavenging activity (RSA%) was in vitro evaluated using ABTS method. FT-IR spectra indicated that GMFX-o-phdn chelated with metal ions as a tetradentate through oxygen of carboxylate group and nitrogen of azomethine group. The data of infrared, 1H NMR, and molar conductivity indicate that GMFX–o-phdn reacted as neutral tetra dentate ligand (N2O2) with metal ions through the two oxygen atoms of the carboxylic group (oxygen containing negative charge) and two nitrogen atoms of azomethine group (each nitrogen containing a lone pair of electrons) (the absent of peak corresponding to ν(COOH) at 1715 cm−1, the shift of azomethine group peak from 1633 cm−1 to around 1570 cm−1, the signal at 11 ppm of COOH and the presence of the chloride ions outside the complex sphere). Thermal analyses (TG-DTG/DTA) exhibited that the decaying of the metal complexes exists in three steps with the final residue metal oxide. The obtained data from DTA curves reflect that the degradation processes were exothermic or endothermic. Results showed that some of the studied complexes exhibited promising antifungal activity against most of the tested fungal pathogens, whereas they showed higher antibacterial activity against E. coli and B. cereus and low activity against P. fluorescens and P. aeruginosa. In addition, GMFX-o-phdn and its metal complexes showed strong antioxidant effect. In particular, the parent ligand and Fe(III) complex showed greater antioxidant capacity at low tested concentrations than that of other metal complexes where their IC50 were 169.7 and 164.6 µg/mL, respectively.

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N. Borase, Jitendra, et Shankarsing S. Rajput. « DESIGN, SYNTHESIS AND BIOLOGICAL PROPERTIES OF TRANSITION METAL COMPLEXES OF SCHIFF BASE LIGAND DERIVED FROM PYRIDINE DERIVATIVES ». Journal of Advanced Scientific Research 13, n^o 10 (3 décembre 2022) : 12–24. http://dx.doi.org/10.55218/jasr.2022131003.

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Novel classes of heterocyclic Schiff base ligand were prepared from the condensation of 2-methoxy benzaldehyde and 2-amino 4-methyl pyridine in absolute ethanol in presence of catalytic amount of dilute HCl. The resulted novel class ofheterocyclic ligand was treated with metal salt or acetate results in the formation of Fe (III), Co (III), Ni (II) & Cu (II)complexes. All newly synthesized resulted ligand its metal complexes were characterized by elemental analysis and FTIR,Magnetic susceptibility, Antimicrobial, Antioxidant, ESR spectrum for Copper complex in DMF solvent recorded atroom temperature. The Electronic spectra and magnetic susceptibility measurements indicates that square planer andoctahedral geometry of these complexes also suggest their structure in which (N, O) group acts as bidentate ligand. Thethermal stability, decomposition behavior has been investigated by using thermo gravimetric analysis at heating rate 10°Cper minute with nitrogen atmosphere and their and kinetic parameter was also calculated by using Freeman Carrollmethod. Screening results of antimicrobial, antioxidant activity of transition metal complexes shows good antibacterialand antifungal activity and excellent antioxidant activity.

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Chopra, S., R. P. Singh et B. S. Pannu. « Thermodynamics of group IIa metal ions complexes of phenetsal ». Thermochimica Acta 129, n^o 2 (juillet 1988) : 345–49. http://dx.doi.org/10.1016/0040-6031(88)87351-9.

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Reid, R. Stephen, et Benjamin Podányi. « A proton nuclear magnetic resonance relaxation study of the glycine, alanine, and lactate complexes of gadolinium(III) in aqueous solution ». Canadian Journal of Chemistry 65, n^o 7 (1 juillet 1987) : 1508–12. http://dx.doi.org/10.1139/v87-258.

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The 1H nuclear magnetic resonance spin-lattice and spin–spin relaxation rate enhancements induced by the gadolinium(III) ion were measured in solutions of glycine, alanine, and sodium lactate containing different amounts of Gd(III). The proton relaxation rates in the Gd(III) complexes were calculated from these data, and were used to calculate metal–hydrogen atom distances. Comparison of these data with corresponding distances calculated from literature X-ray crystallographic data for model compounds shows that in the two amino acid complexes the Gd(III) ion is coordinated in a four-membered ring through the two oxygen atoms of the carboxylate group. By contrast, in the lactate complex coordination is via a five-membered ring involving one oxygen atom of the carboxylate group and the α-hydroxyl oxygen.

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Shadab, Mohd, et Mohammad Aslam. « Synthesis and Characterization of Some Transition Metal complexes with N-phenyl-N’-[substituted phenyl] Thiourea ». Material Science Research India 11, n^o 1 (30 août 2014) : 83–89. http://dx.doi.org/10.13005/msri/110111.

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A series of thiourea ligand , N-N'- diphenyl thiourea [I] [DPTH], N-phenyl-N'-[2-phenoyl] thiourea [II] [PPTH], N-phenyl-N'-[2-chlorophenyl] thiourea III [PCPTH], N-phenyl-N'- [5-chloro-2-methyl phenyl] thiourea IV [PCMPTH] and N- phenyl -N'-(5-chloro-2-methoxy phenyl) thiourea V (PCMTPTH) and their transition metal complexes of the type ML2 and ML2 Cl2 have been synthesized by reacting phenyl isothiocyanate with substituted aniline and transition metal salts. These newly synthesized ligands and their complexes were characterized by elemental and spectral studies. Based upon these studies it was revealed that in all the cases metal is coordinated through suphur group of thioamide of ligands. In case of nickel complexes, the nickel is coordinated to both oxygen and sulphur. In all the complexes metal is tetra coordinated forming a square planer geometry.

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Alnuwaiser, Maha Abdallah. « Antimicrobial Properties of Levofloxacin Antibiotic Complexes of Zirconium(IV) and Indium(III) ». Science of Advanced Materials 12, n^o 8 (1 août 2020) : 1116–24. http://dx.doi.org/10.1166/sam.2020.3778.

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In this article, there are two new levofloxacin (HLevo) complexes were synthesized and spectroscopically discussed. These complexes were prepared in alkaline state (pH = 8) with the 1:1 stoichiometry between zirconyl(II) or indium(III) chloride and pure HLevo antibiotic drug ligand in mixed solvent equal volumes from methanol and bi-distilled water. The structures interpretation were performed based on the micro analytical (elemental analyses), molar conductance and spectroscopic measurements. It is shown that the deprotonated HLevochelate was coordinated towards ZrIV and InIII metal ions, this occurs as a bidentate ligand through the oxygen atoms of carboxylate and carbonyl group, respectively. Accordingly, these complexes can be speculated as [ZrO(Lev)(Cl)(H2O)] · H2O (1) and [In(Lev)(Cl)2(H2O)2] (2). Through Tranmission Electron Microscopy (TEM) imaging it is demonstrated that the nanoscale particles have a homogeneous distribution across the complex surface. Furthermore, by assessing in vitro antimicrobial activities, the inhibition activity of HLevo drug ligand as well as the associated metal ion complexes were evaluated towards specific types of bacteria and fungi.

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Yang, Xuemei, Allen Lunsford et Marcetta Y. Darensbourg. « Connecting Main-Group Metals (Al, Ga, In) and Tungsten(0) Carbonyls via the N2S2 Metallo-Ligand Strategy ». Inorganics 7, n^o 9 (13 septembre 2019) : 115. http://dx.doi.org/10.3390/inorganics7090115.

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Tetradentate N2S2 ligands (such as bismercaptoethanediazacycloheptane in this study) have seen extensive use in combination with transition metals. Well-oriented N2S2 binding sites are ideal for d8 transition metals with square planar preferences, especially NiII, but also as a square pyramidal base for those metals with pentacoordinate preferences, such as [V≡O]2+, [Fe(NO)]2+, and [Co(NO)]2+. Further reactivity at the thiolate sulfurs generates diverse bi, tri, and tetra/heterometallic compounds. Few N2S2 ligands have been explored to investigate the possibility of binding to main group metals, especially group III (MIII) metals, and their utility as synthons for main group/transition metal bimetallic complexes. To open up this area of chemistry, we synthesized three new five-coordinate main group XMN2S2 complexes with methyl as the fifth binding ligand for M = Al, and chloride for M = Ga and In. The seven-membered diazacycle, dach, was engaged as a rigid stabilized connector between the terminal thiolate sulfurs. The pentacoordinate XMN2S2 complexes were characterized by 1H-NMR, 13C-NMR, +ESI-Mass spectra, and X-ray diffraction. Their stabilities and reactivities were probed by adding NiII sources and W(CO)5(THF). The former replaces the main group metals in all cases in the N2S2 coordination environment, demonstrating the weak coordinate bonds of MIII–N/S. The reaction of XMN2S2 (XM = ClGaIII or ClInIII) with the labile ligand W(0) complex W(CO)5(THF) resulted in Ga/In–W bimetallic complexes with a thiolate S-bridge. The synthesis of XMN2S2 complexes provide examples of MIII–S coordination, especially Al–S, which is relatively rare. The bimetallic Ga/In–S–W complex formation indicates that the nucleophilic ability of sulfur is retained in MIII–S–R, resulting in the ability of main group MIII–N2S2 complexes to serve as metalloligands.

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