Synthesis, structure, spectroscopic characterization and catalytic activity of chiral dioxidomolybdenum(VI) Schiff base complexes derived from R(-)-2-amino-1-propanol

摘要

Ten new chiral cis-dioxidomolybdenum(VI) complexes with tridentate Schiff bases were synthesized by monocondensation of R( - )-2-amino-1-propanol with salicylaldehyde and its derivatives. Their spectroscopic properties have been investigated UV-Vis, CD, IR, one- (H-1, C-13) and two-dimensional (COSY, gHSQC and NOESY) NMR techniques. The single-crystal X-ray analysis of the {R( - )-2-[(1-oxidopropyl)iminomethyl]-4-methylphenolato-kappa N-3,O,O'}-(methanol)dioxidomolybdenum(VI) reveals a distorted octahedral geometry. After optimization of reaction conditions, catalytic activity of these complexes in oxidation of olefins, Le. styrene and cyclohexene, with aqueous 30% H2O2 or tert-butyl hydroperoxide (TBHP) as an oxidant were tested. Moreover, the molybdenum(VI) Schiff base complexes are also able to catalyze the oxidation of thioanisole to methyl phenyl sulfoxide in presence of aqueous 30% H2O2.