Vanadium(IV) and-(V) complexes of reduced Schiff bases derived from aromatic o-hydroxyaldehydes and tyrosine derivatives

Isabel Correia, Susana Marcão, Kamila Koci, Isabel Tomaz, Pedro Adão, T. Kiss, T. Jakusch, Fernando Avecilla, João Costa Pessoa

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The reduced Schiff bases of salicylaldehyde and pyridoxal (and o-vaniline) with L-tyrosine (Tyr) and D,L-o-tyrosine (o-Tyr), designated as sal-Tyr (1), sal-o-Tyr (2), pyr-Tyr (3), pyr-o-Tyr (4), and o-van-L-Tyr (5), as well as the oxidovanadium(IV) complex VO(sal-o-Tyr) (6) have been prepared. The compounds have been characterized in the solid state and in solution. The structure of 3 has been determined by X-ray diffraction. Complexation of these ligands with vanadium in aqueous solution has been studied by pH potentiometry, UV/Vis, and circular dichroism (for the L-Tyr derivatives), as well as by EPR for the V IVO systems and 51V NMR for the VVO2 systems. Stoichiometries and complex formation constants have been determined by pH potentiometry (25 °C, I = 0.2 M KCl) 1:1 complexes are formed in most systems with variable protonation states VOLH2 (only with 3 and 4), VOLH, VOL, and VOLH-1. Dinuclear species (VOL)2H and (VOL)2 were identified only in the case of 3. Spectroscopic data provided information about the most probable binding modes for each stoichiometry. The VIVO complexes formed with the o-Tyr-derived ligands are more stable than those with L-Tyr, the more adequate coordination position of the phenolate in the o-Tyr ligands shows a more significant stabilizing effect compared with 3 and 4.

Original languageEnglish
Pages (from-to)694-708
Number of pages15
JournalEuropean Journal of Inorganic Chemistry
Issue number5
DOIs
Publication statusPublished - Feb 2011

Fingerprint

Vanadium
Schiff Bases
Tyrosine
Derivatives
Ligands
Stoichiometry
oligomycin sensitivity-conferring protein
Pyridoxal
Protonation
Complexation
Paramagnetic resonance
Nuclear magnetic resonance

Keywords

  • Coordination modes
  • N-O ligands
  • Potentiometry
  • Structure elucidation
  • Vanadium

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Vanadium(IV) and-(V) complexes of reduced Schiff bases derived from aromatic o-hydroxyaldehydes and tyrosine derivatives. / Correia, Isabel; Marcão, Susana; Koci, Kamila; Tomaz, Isabel; Adão, Pedro; Kiss, T.; Jakusch, T.; Avecilla, Fernando; Costa Pessoa, João.

In: European Journal of Inorganic Chemistry, No. 5, 02.2011, p. 694-708.

Research output: Contribution to journalArticle

Correia, Isabel ; Marcão, Susana ; Koci, Kamila ; Tomaz, Isabel ; Adão, Pedro ; Kiss, T. ; Jakusch, T. ; Avecilla, Fernando ; Costa Pessoa, João. / Vanadium(IV) and-(V) complexes of reduced Schiff bases derived from aromatic o-hydroxyaldehydes and tyrosine derivatives. In: European Journal of Inorganic Chemistry. 2011 ; No. 5. pp. 694-708.
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AU - Marcão, Susana

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AU - Tomaz, Isabel

AU - Adão, Pedro

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AU - Jakusch, T.

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