NORMAL-COORDINATE ANALYSIS OF MSIH(3) MOIETIES IN TRANSITION-METAL COMPLEXES AND COMPARISON TO RESULTS OBTAINED FOR SILYL HALIDES

In order to examine the influence of the transition metal on the metal -silyl fragment MSiH(3) and the metal-silicon bond, polarized Raman sp ectra of the complexes (C(5)R(5))(CO)(2)FeSiH3 [R = H (Cp) (la), Me (C p) (Ib)], (C5H5)(CO)(PPh(3))FeSiH3 (Ic), (C(5)Me(5))(CO)(2)RuSiH3 (2) , (C(5)R(5))(CO)(2)(PMe(3))MoSiH3 [R = H (3a), Me (3b)], and (C(5)R(5) )(CO)(2)(PMe(3))WSiH3 [R = H(4a), Me (4b)] have been recorded. The spe ctral data have been evaluated and interpreted on the basis of a norma l coordinate analysis of the MSiH(3) core and the derived force consta nts and potential energy distributions were compared. to results obtai ned for analogous halogen derivatives in the series XSiH(3) [X = Br (5 ), I (6)].