13019-31-3Relevant articles and documents
Synthesis, Characterization, Reactivity, Catalytic Activity, and Antiamoebic Activity of Vanadium(V) Complexes of ICL670 (Deferasirox) and a Related Ligand
Maurya, Mannar R.,Sarkar, Bithika,Avecilla, Fernando,Tariq, Saba,Azam, Amir,Correia, Isabel
, p. 1430 - 1441 (2016)
The reactions of [VIVO(acac)2] (acac = acetylacetonato) with two ONO tridentate ligands, 4-[3,5-bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]benzoic acid (H2L1, I) and 3,5-bis(2-hydroxyphenyl)-1-phenyl-1,2,4-triazole
Chemoenzymatic Halogenation of Phenols by using the Haloperoxidase from Curvularia inaequalis
Fernández-Fueyo, Elena,Van Wingerden, Marco,Renirie, Rokus,Wever, Ron,Ni, Yan,Holtmann, Dirk,Hollmann, Frank
, p. 4035 - 4038 (2015)
The vanadium-dependent chloroperoxidase from Curvularia inaequalis is an efficient biocatalyst for the in situ generation of hypohalous acids and subsequent electrophilic oxidation/halogenation reactions. Especially, its superb activity and stability unde
Selective Mono- and Dibromination of Thymol by Electrolysis in Acetonitrile and Methanol
Taniguchi, Isao,Takada, Kouzou,Yamaguchi, Hiroko,Yasukouchi, Kazuo
, p. 1693 - 1694 (1984)
For anodic bromination of thymol, MeCN and MeOH were suitable solvents for mono- and dibromination respectively.In MeCN, no dibrominated product was observed even when four Faradays per mole of thymol were passed.
In vitro cytotoxicity and catalytic evaluation of dioxidovanadium(v) complexes in an azohydrazone ligand environment
Mohanty, Monalisa,Maurya, Shailendra K.,Banerjee, Atanu,Patra, Sushree Aradhana,Maurya, Mannar R.,Crochet, Aurélien,Brzezinski, Krzysztof,Dinda, Rupam
, p. 17680 - 17695 (2019)
Three new anionic dioxidovanadium(v) complexes (HNEt3)[VO2(L)1-3] (1-3) of tridentate binegative aroylhydrazone ligands containing the azobenzene moiety were synthesized and structurally characterized. The aroylhydrazone ligands (H2L1-3) were derived from the condensation of 5-(arylazo) salicylaldehyde derivatives with the corresponding aroyl hydrazides. All the synthesized ligands and metal complexes were successfully characterized by several physicochemical techniques, namely, elemental analysis, electrospray ionization mass spectrometry, spectroscopic methods (IR, UV-vis and NMR), and cyclic voltammetry. Single-crystal X-ray diffraction crystallography of 1-3 revealed five-coordinate geometry, where the ligand coordinates to the metal centre in a binegative tridentate O, N, O coordinating anion and two oxido-O atoms, resulting in distortion towards the square pyramidal structure. The complexes were further evaluated for their in vitro cytotoxicity against HeLa and HT-29 cancer cell lines. All the complexes manifested a cytotoxic potential that was found to be comparable with that of clinically referred drugs, while complex 3 proved to be the most cytotoxic among the three complexes for both cell lines, which may be due to the synergistic effect of the naphthyl substituent in the azohydrazone ligand environment coordinated to the vanadium metal. The synthesized complexes 1-3 were probed as catalysts for the oxidative bromination of thymol and styrene as a functional mimic of vanadium haloperoxidases (VHPOs). All the reactions provided high percentages of conversion (>90%) with a high turnover frequency (TOF) in the presence of the catalysts 1-3. In particular, for the oxidative bromination of thymol, the percentage of conversion and TOF were in the ranges of 98-99% and 5380-7173 (h-1), respectively. Besides, 3 bearing the naphthyl substituent showed the highest TOF among all the complexes for the oxidative bromination of both thymol and styrene.
Vanadium(v) complexes of a tripodal ligand, their characterisation and biological implications
Maurya, Mannar R.,Uprety, Bhawna,Avecilla, Fernando,Ad?o, Pedro,Costa Pessoa
, p. 17736 - 17755 (2015)
The reaction of the tripodal tetradentate dibasic ligand 6,6′-(2-(pyridin-2-yl)ethylazanediyl)bis(methylene)bis(2,4-di-tert-butylphenol), H2L1I, with [VIVO(acac)2] in CH3CN gives the VVO-complex, [VVO(acac)(L1)] 1. Crystallisation of 1 in CH3CN at ～0 °C gives dark blue crystals of 1, while at room temperature it affords dark green crystals of [{VVO(L1)}2μ-O] 3. Upon prolonged treatment of 1 in MeOH, [VVO(OMe)(MeOH)(L1)] 2 is obtained. All three complexes were analysed by single-crystal X-ray diffraction, depicting a distorted octahedral geometry around vanadium. In the reaction of H2L1 with VIVOSO4 partial hydrolysis of the tripodal ligand results in the elimination of the pyridyl fragment of L1 and the formation of H[VVO2(L2)] 4 containing the ONO tridentate ligand 6,6′-azanediylbis(methylene)bis(2,4-di-tert-butylphenol), H2L2II. Compound 4, which was not fully characterised, undergoes dimerization in acetone yielding the hydroxido-bridged [{VVO(L2)}2μ-(OH)2] 5 having a distorted octahedral geometry around each vanadium. In contrast, from a solution of 4 in acetonitrile, the dinuclear compound [{VVO(L2)}2μ-O] 6 is obtained, with a trigonal bipyramidal geometry around each vanadium. The methoxido complex 2 is successfully employed as a functional catechol-oxidase mimic in the oxidation of catechol to o-quinone under air. The process was confirmed to follow a Michaelis-Menten type kinetics with respect to catechol, the Vmax and KM values obtained being 7.66 × 10-6 M min-1 and 0.0557 M, respectively, and the turnover frequency is 0.0541 min-1. A similar reaction with the bulkier 3,5-di-tert-butylcatechol proceeded at a much slower rate. Complex 2 was also used as a catalyst precursor for the oxidative bromination of thymol in aqueous medium. The selectivity shows quite interesting trends, namely when not using excess of the primary oxidizing agent, H2O2, the para mono-brominated product corresponds to ～93% of the products and no dibromo derivative is formed.
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Pearson,D.E. et al.
, p. 2358 - 2360 (1967)
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4,6-Diacetyl Resorcinol Based Vanadium(V) Complexes: Reactivity and Catalytic Applications
Maurya, Mannar R.,Jangra, Nancy,Avecilla, Fernando,Correia, Isabel
, p. 314 - 329 (2019/01/24)
Four ONO donor ligands are isolated from the condensation of 4,6-diacetyl resorcinol with isonicotinoyl hydrazide (H2dar-inh, I), nicotinoyl hydrazide (H2dar-nah, II), benzoyl hydrazide (H2dar-bhz, III), and 2-furoyl hydrazide (H2dar-fah, IV) on refluxing in MeOH. The reaction of in situ generated aqueous K[H2VVO4] with ligands I–IV at neutral pH gives complexes [K(H2O)2][VO2(dar-inh)] (1), [K(H2O)2][VO2(dar-nah)] (2), [K(H2O)2][VO2(dar-bhz)] (3), and [K(H2O)2][VO2(dar-fah)] (4), respectively. The reaction of [VIVO(acac)2] (acac = acetylacetonato) with these ligands (I–IV) under aerobic conditions in methanol yields oxidomethoxidovanadium(V) complexes [VO(OMe)(MeOH)(dar-inh)] (5), [VO(OMe)(MeOH)(dar-nah)] (6), [VO(OMe)(MeOH)(dar-bhz)] (7), and [VO(OMe)(MeOH)(dar-fah)] (8). All the isolated complexes are characterized by elemental, thermal, electrochemical, and spectroscopic techniques [FTIR, UV/Vis, NMR (1H, 13C and 51V NMR)], and single-crystal X-ray diffraction analysis (for 1, 6, 7, and 8). X-ray analysis confirms the coordination of the ligands through Ophenolate, Nazomethine, and Oenolate to the metal center. In the molecular structure of [K(H2O)(EtOH)][VVO2(dar-inh)] (abbreviated as 1a where one molecule of water is replaced by EtOH), water molecules act as bridges between two K+ ions and the complex shows a dimeric structure due to the presence of electrostatic interactions between V=O oxygen atoms with K+ ions. These complexes are active catalysts for the oxidative bromination of thymol in the presence of KBr, HClO4, and H2O2 and give 2-bromothymol, 4-bromothymol, and 2,4-dibromothymol as major products. Complexes 1–4 were also tested as catalysts for the epoxidation of various alkenes (namely styrene, cyclohexene, cis-cyclooctene, 1-hexene, 1-octene, cyclohexenone, and trans-stilbene) with H2O2 in the presence of NaHCO3 as promoter, giving the corresponding epoxides selectively.
