A novel vanadium(V) phosphate and the arsenate analogue, [(VO(2))(2)(4,4'-bpy)(0.5)(4,4'-Hbpy)(XO(4))].H(2)O (X = P, As; bpy = bipyridine), have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. They are the first structurally characterized compounds in the vanadium(V)/4,4'-bpy/phosphate (or arsenate) systems. The two compounds are isostructural and crystallize in the triclinic space group P macro (No. 2) with a = 7.9063(3) A, b = 10.2201(4) A, c = 12.1336(5) A, alpha = 113.4652(7) degrees, beta = 95.7231(7) degrees, gamma = 94.4447(7) degrees, and Z = 2 for the phosphate, and a = 7.8843(6) A, b = 10.3686(7) A, c = 12.2606(9) A, alpha = 113.464(1) degrees, beta = 95.560(1) degrees, gamma = 94.585(1) degrees, and Z = 2 for the arsenate. The structure consists of phosphate-bridged vanadium(V) double chains linked through 4,4'-bpy ligands to form a sheet with the monoprotonated 4,4'-Hbpy(+) ligand being coordinated to the metal atom as a pendent group. The (1)H MAS NMR spectrum exhibits four resonances at 14.2, 9.5, 7.2, and 3.7 ppm with an intensity ratio close to 1:6:6:2, corresponding to three different types of protons in 4,4'-bpy and 4,4'-Hbpy(+) and one type of protons in H(2)O. The peak at 14.2 ppm can be assigned to the proton bonded to the pyridine nitrogen atom, which confirms the presence of 4,4'-Hbpy(+).
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http://dx.doi.org/10.1021/ic0111841 | DOI Listing |
J Hazard Mater
November 2024
Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264000, China. Electronic address:
Microbial-driven V(V) reduction plays a crucial role in its biogeochemical cycle, yet the mechanisms underlying this bioreduction remain inadequately understood. While the effectiveness of organic compounds as electron donors in facilitating bacterial reduction of V(V) has been established, the role of inorganic electron donors in initiating this process at the level of pure cultured bacteria has not been explored. In this study, we report on a marine Shewanella sp.
View Article and Find Full Text PDFDalton Trans
December 2023
State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
The triazolate-assisted asymmetric dinuclear oxovanadium(IV) citrate [VO(cit)(Hdatrz)]·5HO (1, Hcit = citric acid, Hdatrz = 1-1,2,4-triazole-3,5-diamine) and its additive salt [VO(cit)(Hdatrz)][VO(cit)]·2Hdatrz·9.5HO (2) and the polymerized hexanuclear product [VO(μ-O)(cit)(Hdatrz)]·4HO (3) have been isolated at different temperatures, respectively. Adduct 2 shows strong evidence for the conversion of a symmetric dinuclear oxovanadium(IV) citrate to a mixed-ligand asymmetric oxovanadium(IV) citrate.
View Article and Find Full Text PDFInorg Chem
December 2023
Department of Chemistry, University of Cyprus, Nicosia 2109, Cyprus.
Based on the strong binding and high selectivity properties of 2,6-bis[hydroxy(methyl)amino]-4-morpholino-1,3,5-triazine (Hbihyat) for [UO], novel binucleating ligands (BLs) ,',″,-((1,4-phenylenebis(oxy))bis(1,3,5-triazine-6,2,4-triyl))tetrakis(-methylhydroxylamine) (Hqtn), ,-bis(4,6-bis(hydroxy(methyl)amino)-1,3,5-triazin-2-yl)benzene-1,4-diamine (Hpdl), and ,-bis(4,6-bis(hydroxy(methyl)amino)-1,3,5-triazin-2-yl)ethane-1,2-diamine (Henl) were synthesized. Binuclear complexes formed by coordination of hard metal ions with Hqtn are thermodynamically more stable than their mononuclear analogues with Hbihyat due to the increase in entropy accompanying the formation of more chelate rings. Reaction of either Hqtn or Hpdl or Henl with [UO] and [VO] resulted in the isolation of the binuclear complexes [(UO)(μ-qtn)(HO)] (), [(VO)(μ-qtn)][PPh][PPh4] (), [(UO)(μ-pdl)(HO)(MeOH)] (), [(VO)(μ-pdl)][PPh] (), [(UO)(μ-enl)(HO)] (), and [(VO)(μ-enl)][PPh] ().
View Article and Find Full Text PDFDalton Trans
December 2023
Dipartimento di Farmacia, University of Pisa, Via Bonanno 33, 56126 Pisa, Italy.
A panel of novel vanadium(IV)-betaine complexes has been synthesized according to new and efficient methodologies and characterized through both spectroscopic techniques and thermal analyses. Vanadium(IV)-betaine solutions have been electrochemically oxidized and the effect of betaine ligands on the thermal and pH stability of vanadium(V) solutions has been evaluated under different temperature and acidity conditions. The obtained results displayed a remarkable effect for both of the examined parameters, achieving the preparation of aqueous vanadium(V) solutions displaying long term stability at more than 55 °C under mild acidic conditions.
View Article and Find Full Text PDFInorg Chem
October 2023
School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
Limited stability of most transition-metal complexes in biological media has hampered their medicinal applications but also created a potential for novel cancer treatments, such as intratumoral injections of cytotoxic but short-lived anticancer drugs. Two related V(V) complexes, [VO(Hshed)(dtb)] () and [VO(Hshed)(cat)] (), where Hshed = -(salicylideneaminato)--(2-hydroxyethyl)-1,2-ethanediamine, Hdtb = 3,5-di--butylcatechol, and Hcat = 1,2-catechol, decomposed within minutes in cell culture medium at 310 K ( = 43 and 9 s for and , respectively). Despite this, both complexes showed high antiproliferative activities in triple-negative human breast cancer (MDA-MB-231) cells, but the mechanisms of their activities were radically different.
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