Fist Oxidovanadium Complexes Containing Chiral Derivatives of Dihydrophenanthroline and Diazafluorene

Reactions of VCl3 with chiral derivatives of dihydrophenanthroline (2R,4R,9R,11R)-3,3,10,10-tetramethyl-1,2,3,4,6,7,9,10,11,12-decahydro-2,4:9,11-dimethanodibenzo[b,j][1,10]phenanthroline (L1) and diazafluorene (1R,3R,8R,10R)-2,2,9,9-tetramethyl-2,3,4,7,8,9,10,12-octahydro-1H-1,3:8,10-dimethanocyclopenta[1,2-b:5,4-b′]diquinoline (L2) in acetonitrile in air yield mixtures of [VIII(L1/L2)(CH3CN)Cl3] and [VIVO(L1/L2)(CH3CN)Cl2] (I, II) which were characterized by elemental analysis, IR spectroscopy and magnetic susceptibility data. The behavior of these mixtures in different solvents was investigated by 51V NMR and EPR spectroscopies as well as optical rotation. Recrystallization of a [VIII(L1)(CH3CN)Cl3]/[VIVO(L1)(CH3CN)Cl2] mixture from CH2Cl2/Et2O affords a V(IV) complex, [VIVO(L1)(H2O)Cl2]·nCH2Cl2 (III). Recrystallization from MeOH/Et2O leads to complete oxidation to V(V) complex [VVO(L1)(OMe)Cl2] (IV), which was characterized by X-ray crystallography, IR, 51V and 1H NMR spectroscopies.