Author Institution: Department of Chemistry, Geneva CollegeThe vibrational infrared spectrum of dimethylsulfide-borane in the liquid (25βC) and solid (β196βC) states was studied from 4000 to 400cmβ1 as well as the Raman spectrum of the liquid sample. In addition the vibrational spectra of (CH3β)2βSB10H3β and (CH3β)2βSBD3β were studied. The observed frequencies of the various samples and their assignments will be discussed on the basis of a Cββββ molecular model for dimethylsulfide-borane