Normal coordinate analysis of M-Si(2)H(5)-moieties in transition metal complexes and comparison to Br-Si(2)H(5)

In order to examine the influence of the transition metal on the metal-disilanyl-fragment and especially the M-Si and Si-Si-bond polarized Raman spectra of the complexes (C(5)R(5))(CO)(2)Fe-Si(2)H(5) {R=H ( 1a); R=Me ( 1b)} and (C(5)R(5))(CO)(2)(PMe(3))M-Si(2)H(5) {R=Me, M=Mo ( 2); R=H, M=W ( 3)} have been recorded. The spectral data have been evaluated and interpreted on the basis of a normal coordinate analysis of the M-SiH(2)-Si-fragment including Br-Si(2)H(5) ( 4) and comparison with examinations of the M-SiH(3)-fragment.