Complex formation between oxovanadium(IV) and several diazole derivatives (imidazole-4-acetic, imidazole-4,5-dicarboxylic and pyrazole-3,5-dicarboxylic acid) was studied in aqueous solution by pH-potentiometric and spectroscopic (electron paramagnetic resonance and electronic absorption) techniques. The results show that the imidazole-4-acetate ligand, being suitable for bidentate coordination, forms monomeric or mixed hydroxo-bridged species. In the case of the dicarboxylic acids both having two bidentate sites for metal binding the formation of tetrameric or dimeric complexes is strongly favored. Pyrazole-3,5-dicarboxylic acid forms dinuclear, while imidazole-4,5-dicarboxylic acid forms cyclic tetrameric species, both types containing diazolate bridges. There is evidence for the VO2+-supported deprotonation of the imidazole N-1 (pyrrole-type) group at pH as low as 5 in aqueous solution. (C) 1998 Elsevier Science S.A.

Oxovanadium(IV) complexes of imidazole-4-acetic, imidazole-4,5-dicarboxylic and pyrazole-3,5-dicarboxylic acids / Sanna, D; Micera, Giovanni; Buglyo, P; Kiss, T; Gajda, T; Surdy, P.. - In: INORGANICA CHIMICA ACTA. - ISSN 0020-1693. - 268:2(1998), pp. 297-305. [10.1016/S0020-1693(97)05761-7]

Oxovanadium(IV) complexes of imidazole-4-acetic, imidazole-4,5-dicarboxylic and pyrazole-3,5-dicarboxylic acids

MICERA, Giovanni;
1998-01-01

Abstract

Complex formation between oxovanadium(IV) and several diazole derivatives (imidazole-4-acetic, imidazole-4,5-dicarboxylic and pyrazole-3,5-dicarboxylic acid) was studied in aqueous solution by pH-potentiometric and spectroscopic (electron paramagnetic resonance and electronic absorption) techniques. The results show that the imidazole-4-acetate ligand, being suitable for bidentate coordination, forms monomeric or mixed hydroxo-bridged species. In the case of the dicarboxylic acids both having two bidentate sites for metal binding the formation of tetrameric or dimeric complexes is strongly favored. Pyrazole-3,5-dicarboxylic acid forms dinuclear, while imidazole-4,5-dicarboxylic acid forms cyclic tetrameric species, both types containing diazolate bridges. There is evidence for the VO2+-supported deprotonation of the imidazole N-1 (pyrrole-type) group at pH as low as 5 in aqueous solution. (C) 1998 Elsevier Science S.A.
1998
Oxovanadium(IV) complexes of imidazole-4-acetic, imidazole-4,5-dicarboxylic and pyrazole-3,5-dicarboxylic acids / Sanna, D; Micera, Giovanni; Buglyo, P; Kiss, T; Gajda, T; Surdy, P.. - In: INORGANICA CHIMICA ACTA. - ISSN 0020-1693. - 268:2(1998), pp. 297-305. [10.1016/S0020-1693(97)05761-7]
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11388/57076
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 36
social impact