THEORETICAL EVALUATION OF STERIC EFFECTS IN [REH5(PR(3))(2)(SIR(3))(2)] COMPLEXES WITH THE IMOMM METHOD

A theoretical study including full geometry optimizations is carried o ut at the IMOMM(MP2:MM3) (IMOMM = integrated molecular orbital molecul ar mechanics) computational level on the [ReH5(PPh(i)Pr(2))(2)(SiHPh(2 ))(2)] and [ReH5(PCyp(3))(2)(SiH(2)Ph)(2)] systems, the results being compared with available experimental diffraction data, as well as with MP2 results on the model system [ReH5(PH3)(2)(SiH3)(2)]. A simple sch eme for the analysis of the relative weight of different contributions to the ''steric'' distortion is also proposed and applied to the same [ReH5(PPh(i)Pr(2))(2)(SiHPh(2))(2)] and [ReH5(PCyp(3))(2)(SiH(2)Ph)(2 )] species.