Vibrational spectroscopic analysis of chlorosilanes and siloxane oligomers: implications for the spectra of polydimethylsiloxanes.

Inelastic neutron scattering spectra of the polydimethylsiloxane polymer models, methyltrichlorosilane (MTCS), dimethyldichlorosilane (DMDCS), trimethylchlorosilane (TMCS), hexamethyldisiloxane (HMDS), and octamethyltrisiloxane (OMTS), are reported and assigned by comparison with ab initio calculations. Also reported are the spectra of a series of polydimethylsiloxane samples with viscosities in the range 5-100 cSt, based on the model compounds and calculated spectra of a short polydimethylsiloxane, and the spectrum of polydimethylsiloxane is reassigned. Also reported are the infrared (IR) and Raman spectra of TMCS and OMTS.