A Raman study of H₂O₂ and D₂O₂ vapor

Abstract

Abstract The Raman spectrum of hydrogen peroxide in the vapor phase has been measured for the first time by means of an Ar + laser source. Three parallel bands were found at 3607 ( v 1 ), 1393.5 ( v 2 ), and 863.5 ( v 3 ) cm −1 , with relative intensities of about 10:3:12. In deuterium peroxide the corresponding frequencies are 2668.5, 1028.5, and 867.0 cm −1 , and the relative intensities, 20:3:12. Thus, the OO stretching frequency is appreciably lower in the free molecule than in condensed phases (880 cm −1 ). The shift corresponds to a bond shortening of about 0.01 Å in the latter, in agreement with X‐ray and neutron diffraction data for various crystals. The slight shift to higher frequency of the OO vibration in D 2 O 2 is due primarily to coupling with the OD bending, as indicated by a normal coordinate analysis.