Synthesis and characterization of 8-quinolinolato vanadium(IV) complexes

Kentaro Takano, Yukinari Sunatsuki, Masaaki Kojima, Isamu Kinoshita, Takashi Shibahara

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Reaction of vanadium(III) chloride with 8-quinolinol (Hqn) gave a mononuclear vanadium(IV) complex, [VOCl2(H2O)2] 1) · 2H2qn · 2Cl · CH3CN, and three dinuclear vanadium(IV) complexes: [V2O2Cl2(qn)2(H2O )2] (2) · Hqn, [V2O2Cl2(qn)2(C3H 7OH)2] (3), and [V2O2Cl2(qn)2(C4H 9OH)2] (4). Reaction of vanadium(III) chloride with 5-chloro-8-quinolinol (HClqn) gave four dinuclear vanadium(IV) complexes: [V2O2Cl2(Clqn)2(H2 O)2] (5) · 2HClqn, [V2O2Cl2(Clqn)2(C3 H7OH)2] (6), [V2O2Cl2(Clqn)2(C6 H5CH2OH)2] (7), and [V2O2Cl2(Clqn)2(C4 H9OH)2] (8) · 2C4H9OH. Reaction of vanadium(III) chloride with 5-fluoro-8-quinolinol (HFqn) gave two dinuclear vanadium(IV) complexes: [V2O2Cl2(Fqn)2(H2 O)2] (9) · HFqn · 2H2O and V2O2Cl2(Fqn)2(C3H 7OH)2] (10). X-ray structures of 1 · 2H2qn · 2Cl · CH3CN, 3, 4, 6, 7, 8 · 2 t-BuOH, and 10 have been determined. As to the mononuclear species 1 · 2H2qn · 2Cl · CH3CN, coordination of Hqn to vanadium does not occur, but protonation to Hqn occurs to give H2qn+, which links 1's through hydrogen bonding, while each of the dinuclear species has a terminal and a bridging qn (or Clqn, Fqn) ligand, giving rise to a (V-O)2 ring. Magnetic measurements of 3, 4, 6, 7, and 10 in solid form show very weak antiferromagnetic behavior, and the effective magnetic moments are close to spin only value (2.44) of d1-d1 system, while ESR of 3 in THF shows dissociation to monomeric species. Change from mononuclear, 1, to dinuclear, 2, species was followed by the change of electronic spectrum.

Original languageEnglish
Pages (from-to)3201-3207
Number of pages7
JournalInorganica Chimica Acta
Volume362
Issue number9
DOIs
Publication statusPublished - Jul 1 2009

Keywords

  • 8-Quinolinol
  • ESR
  • Electronic spectra
  • Magnetic measurements
  • Vanadium complexes
  • X-ray structures

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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