NORMAL-COORDINATE ANALYSIS, INFRARED-SPEC TRUM, RAMAN-SPECTRUM OF 2,2-DIMETHYLTRISILANE

The Infrared and Raman vibrational spectra of (H3Si)(2)SiMe(2) and (D( 3)Si(2)SiMe(2) have been measured and assigned with the help of a norm al coordinate analysis using the FG formalism. The skeletal deformatio n modes delta, rho, gamma, tau SiC2 and delta SiSiSi of the molecule a re not coupled with motions of the hydrogen atoms and can be regarded as ''unperturbed'' deformation vibrations of the SiSiC2Si atom arrange ment. Their knowledge facilitates the interpretation of the vibrationa l spectra of methylated chainlike silanes in the low frequency region between 250 and 100 cm(-1).