The oxidation of oxovanadium(IV) complexes [LVIVO] (L = tetradentate Schiff-base ligands such as N,N′-ethylenebis- (salicylideneaminate)(2-) (salen) and N,N′ -2,2-dimethylpropylenebis(salicylideneaminate)(2-) (salpn)) to [LVVO]+, believed to be responsible for the voltammetric response near 0.6 V vs Ag/AgC in CH2Cl2 in the presence of tetrabutylammonium tetrafluoroborate as a supporting electrolyte, is in fact coupled to a homogeneous process where [LVO]+ coordinates BF4- to form a neutral complex formulated as [LVOBF4]. The formation constants for [VO(salen)BF4] and [VO(salpn)BF4] are evaluated to be Ksalen-1 = 1.1 × 102 M-1 and Ksalpn-1 = 1.4 × 10 M-1, respectively. Crystal structure of [VO(salen)BF4] reveals that one of the fluorine atoms in BF4- is so close to the vanadium(V) atom as to be practically bound in the solid state.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry