Author Institution:The infrared and Raman spectra of gaseous B5βH9β have been recorded. The spectra are complicated by the existence of a mixture of boron isotopes, but a complete vibrational assignment will be proposed. A number of interesting features appear in the spectra of the vapor, and these will be discussed. Additionally, the Raman spectra of the neat liquid have been studied as a function of temperature. Line widths indicate that the vibrational dephasing times at room temperature are on the order of 2.5 psc. Estimates of the reorientational relaxation are consistent with previous nmr studies