Selenium compounds vibrational spectra

Raman and infrared spectra of a-monoclinic selenium have been reported (3c,d, 4b, 14, 37) the low-temperature Raman spectrum is shown in Fig. 5. It differs sufficiently from that of Se6 for both compounds to be detected in this way in mixtures with each other (15). The observed wave numbers have been assigned to the 11 fundamental modes of the Seg molecule, assuming Z)4d symmetry (see Table V). The ft2 and e modes are infrared active, and the ai, e2, and e3 vibrations are Raman active. The wave number of the inactive b fundamental has been estimated from the second-order Raman spectrum. 

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