RAMAN-SPECTROSCOPY OF PH3 AND PH2 AT HIGH-TEMPERATURE AND SIMULATION OF PH3 RAMAN-SPECTRUM

Experimental Raman spectra of the symmetric stretching vibration band nu-1 and of the degenerate stretching vibration band nu-3 of PH3 were obtained for temperatures ranging from 293 to 903 K. These spectra also show a band of a new gaseous species, which is a pyrolysis product of PH3. This band can be unambiguously attributed to PH2. To extract the Raman spectrum of PH2 from the overall spectrum, the PH3 Raman spectra of the nu-1 and nu-3, bands were calculated. The way in which these bands were calculated is explained and a comparison is made between the experimental and simulated spectra at different temperatures. These comparisons clearly identify the PH2 nu-1 band. By the subtraction of the simulated spectrum from the experimental spectrum, the origin of the PH2 nu-1 band is estimated to be 2310.3 +/- 2 cm-1.