The applicability of laser-Raman spectroscopy to the study of structures of gaseous inorganic species at elevated temperatures (to 1000°C) has been demonstrated.1–6 Several studies have provided information on thermodynamic quantities,2 chemical equilibria,4, 6 and force constants2, 5 for both pure materials and mixtures. In a number of cases, however, strong resonance fluorescence has obscured the vibrational Raman spectra of the species present.3, 4 The source of this resonance fluorescence can be either the material under investigation4 or a species formed through disproportionation of the sample material. An example of the latter case is the resonance fluorescence of BiCl, which overlaps the gas phase Raman scattering of BiCl3.