Vanadium(II)-diamine complexes: synthesis, UV-Visible, infrared, thermogravimetry, magnetochemistry and INDO/S characterisation

Niedwieski, Antonio Carlos; Hitchcock, Peter B.; Neto, Joaquim Delphino Da Motta; Leigh, G. J.; Nunes, Fábio Souza

doi:10.1590/s0103-50532003000500009

Cited by 11 publications

(4 citation statements)

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“…The vanadium(II) ion occupies an octahedral environment, with the chloride ligands bound axially to it at a distance of 2.4888 (7) A Ê , with a Cl i ÐVÐCl angle of 178.11 (4) (symmetry code as in Table 1). The same con®guration was reported for related bis(diamine) complexes, [VCl 2 (diamine) 2 ] (diamine: tmeda = N,N,N H ,N Htetramethylethane-1,2-diamine and deeda = N,N H -diethylethane-1,2-diamine), where VÐCl distances of 2.487 (1) and 2.4936 (14) A Ê , respectively, were found (Niedwieski et al, 2003). The octahedron is distorted, due to the space requirements of the bulky dtbeda.…”

Section: Commentsupporting

confidence: 80%

“…However, this mechanism is not completely understood. Apparently, the self-assembly is strongly dependent on the electronic and steric effects imposed by the diamine (Niedwieski et al, 2003). This present work is part of a systematic study of the electronic and steric effects which govern the thermodynamic stability and reactivity of trans-[VCl 2 (diamine) 2 ] complexes toward the formation of the trinuclear species.…”

Section: Commentmentioning

confidence: 97%

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Dichlorobis(tetrahydrofuran)(N,N′-di-tert-butylethane-1,2-diamine)vanadium(II)

et al. 2003

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Key indicatorsSingle-crystal X-ray study T = 173 K Mean '(C±C) = 0.005 A Ê R factor = 0.053 wR factor = 0.137 Data-to-parameter ratio = 22.8 For details of how these key indicators were automatically derived from the article, seeThe title complex, [VCl 2 (dtbeda)(thf) 2 ] (dtbeda is N,N H -ditert-butylethane-1,2-diamine), was prepared from the reaction of [V 2 Cl 3 (thf) 6 ] 2 [Zn 2 Cl 6 ] with dtbeda in re¯uxing thf. The crystal structure of [VCl 2 (dtbeda)(thf) 2 ] exhibits chlorides in trans positions in a distorted octahedral geometry around the vanadium site. The asymmetric unit consists of one-half of the complex, which is located on a twofold rotation axis in space group C2/c.

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Section: Commentsupporting

confidence: 80%

Section: Commentmentioning

confidence: 97%

Dichlorobis(tetrahydrofuran)(N,N′-di-tert-butylethane-1,2-diamine)vanadium(II)

et al. 2003

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“…Our results (both in vitro and in vivo ) provide experimental evidence that oxovanadium (IV) complex has the potential to be anticancer complex against human cancer cells. Redox‐active vanadium (III) complexes having planar N‐donor heterocyclic ligands are found to be nuclease active (28,29). Apart from antitumor activity, we have developed cell homing peptides conjugated to the developed system and evaluated that the complexes activate glycogen synthesis in rat adipocytes.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Oxovanadium(IV) Schiff base Complexes derived from C‐substituted Diamines and Pyridoxal‐5‐Phosphate as Antitumor Agents

et al. 2012

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Oxovanadium (IV) complexes of N,N¢-bispyridoxyl-5, 5¢-bis (phosphate) ethylenediimine (L1) and N,N¢-bis(pyridoxyl)-5,5¢-bis(phosphate)-1¢¢-(p-nitrobenzyl)ethylenediimine (L2) were synthesized by condensation of optically active C-substituted diamines and pyridoxal-5-phosphate. Oxovanadium (IV) complexes derived from L1 and L2 were evaluated as DNA cleavage agent (cleavage of supercoiled plasmid pBR322 DNA). Interestingly, both the oxovanadium (IV) complexes exhibited DNA nuclease activity, and the extent of oxidation of DNA by these vanadyl complexes was superior to VOSO 4 . The significant reduction in primary tumor and increased delay in tumor growth of 15 days was seen in the tumor regression analysis with oxovanadium (IV) complex of L1. With the preliminary studies performed with the pyridoxal-5-phosphate -based salen derivatives including the cytotoxicity and tumor regression, it is evident that the salen bifunctional chelating agent has obtained therapeutic potential if conjugated to a gene-specific targeting molecule for the oxidation of guanine residue.

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“…Moreover, the significant role of vanadium complexes in biological nitrogen fixation, haloperoxidation, catecholase [17,18] and antimicrobial activity [19] has drawn a particular attention. The coordinated form of vanadium as oxovanadium(IV) and (V) ions i.e., VO 2+ , VO 3+ , VO 2 + and VO(O 2 ) + has gathered tremendous research interest.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Biological Activity of Oxidovanadium(IV) Hydroxamate Complexes Supported by Density Functional Theory

Sharma¹,

Das

Sadhu³

et al. 2021

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The oxidovanadium(IV) complex [VO(HL)2] (1) (where, HL = 4-nitrocinnamohydroxamate; 4-NO2C6H4CH=CHCONHOH) has been synthesized by the condensation reaction of VOSO4∙5H2O and potassium 4-nitrocinnamohydroxamate in methanol-water medium. The complex is characterized by elemental analysis, molar conductivity, magnetic susceptibility measurement, FTIR, UV-Vis, Electron Paramagnetic Resonance (EPR) spectral techniques and mass spectrometry. The bidentate linkage of hydroxamate ligand involving O,O-coordination through hydroxamic and carbonyl oxygen atoms has been deduced. The magnetic susceptibility, EPR and mass spectra (ESI-MS) indicate that the complex exists as monomer and a distorted square pyramidal geometry around vanadium is proposed. The electrochemical study of 1 has shown it is to be electrochemically active exhibiting VOV/VOIV quasi-reversible redox couple. The thermal study of the complex yielded VO2 as sole decomposition product. The coordination compounds 2 and 3 have been isolated from the reaction of complex 1 with 2-cyanopyridine (2-CNPy) and 4-aminobenzonitrile (4-CNAn) respectively and characterized by physicochemical and IR spectral study. The biological activity of 1-3 has been studied against various pathogenic bacteria E. coli, S. aureus, S. typhi, S. paratyphi, S. epidermidis, K. pneumonia and fungi C. albicans, B. fulva, and F. oxysporum by minimum inhibitory concentration (MIC) method. The complexes exhibit enhanced antimicrobial activity relative to both the free ligand and vanadyl sulphate. The cytotoxicity of 1-3 has been studied on mammalian transformed cell line Hep2c, a derivative of human cervix carcinoma HeLa cells by MTT assay. 2 and 3 exhibit higher cytotoxic activity than 1 and reveal a marked effect of the coordination of nitrogen bases. Density functional theory studies have been carried out to determine the relative free energy of formation and stable molecular structures of 1-3. Time dependent density functional theory (TD-DFT) based calculation have been performed to find out the frontier molecular orbitals and to corroborate with the experimentally observed UV-Vis spectrum of 1. Other parameters like HOMO, and LUMO energies, density of state (DOS), and global reactivity descriptors clearly support higher biological activity of 2 and 3 than 1.

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Vanadium(II)-diamine complexes: synthesis, UV-Visible, infrared, thermogravimetry, magnetochemistry and INDO/S characterisation

Abstract: A série de complexos de vanádio(II), [VCl 2 (diamina) 2 ] (diamina = dmeda:

Cited by 11 publications

References 13 publications

Dichlorobis(tetrahydrofuran)(N,N′-di-tert-butylethane-1,2-diamine)vanadium(II)

Dichlorobis(tetrahydrofuran)(N,N′-di-tert-butylethane-1,2-diamine)vanadium(II)

Synthesis of Oxovanadium(IV) Schiff base Complexes derived from C‐substituted Diamines and Pyridoxal‐5‐Phosphate as Antitumor Agents

Synthesis, Characterization, and Biological Activity of Oxidovanadium(IV) Hydroxamate Complexes Supported by Density Functional Theory

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