Influence of structural and electronic properties of organomolybdenum(II) complexes of the type[CpMo(CO)3R] and [CpMo(O2)(O)R] (R = Cl, CH3, CF3) on the catalytic olefin epoxidation

Six compounds of the type[CpMo(CO)(3)R] (R = Cl (1), CH3 (2), CF3 (3)) and [CpMo(O-2)(O)R] (R = Cl (4), CH3 (5), CF3 (6) (Cp = eta(5)-cyclopentadienyl)) have been synthesised and characterised. The crystal structures of [CpMo(CO)(3)CF3] and [CpMo(O-2)(O)CF3] are compared to their literature known chloro and methyl derivatives. The influence of the groups R on the performance as epoxidation catalysts is examined. DFT calculations, IR-spectroscopy and X-ray crystallography help to explain differences in reactivity and enable a rational design of active molybdenum tricarbonyl and oxo-peroxo complexes.