Geometrical isomerization of fac/mer-Mo(CO)3(phosphite)3 and cis/trans-Mo(CO)4(phosphite)2 catalyzed by Me3SiOSO2CF3

Geometrical isomerization of fac-Mo(CO)3L3 (L = P(OPh)3, P(OMe)3, P(OEt)3) to the mer form and that of cis-Mo(CO)4L2 (L = P(OPh)3, P(OMe)3, PPh2(OMe)) to the trans form were observed in CH2Cl2 at room temperature in the presence of a catalytic amount of Me3SiOSO2CF3 (TMSOTf). Crossover experiments suggest that a ligand dissociation is not involved in the isomerization. A catalytic cycle involving an interaction of the silicon atom in Me3Si+ with one oxygen in P(OR)3 ligands has been proposed. The first isolation and the X-ray structure analysis were attained for mer-Mo(CO)3{P(OPh)3}3 through the TSMOTf-assisted isomerization of fac-Mo(CO)3{P(OPh)3}3.