Raman and infrared spectral studies of selena, sulphinyl, sulphonyl and tellura methyl laurates.

Raman spectra (300–1200 cm−1) have been recorded for all the positional isomers of the selena (X=Se), sulphinyl (X=SO) and sulphonyl (X=SO2) methyl laurates CH3(CH2)nX(CH2)mCO2CH3, (n+m =9). The Raman spectra of two isomers of the tellura series (X=Te) were also obtained as were the IR spectra of the sulphonyl series. The SeC2 and TeC2 moieties each give two characteristic Raman bands at 564 and 651 cm−1 and 510 and 600 cm−1 respectively. The SO group gives a characteristic Raman band at 1016 cm−1. The symmetric stretching and bending modes of the SO2 group can be observed in both the IR and Raman spectra at 1109 and 517 cm−1 respectively. These quoted values do change when the functional group is near the carbonyl group or towards the end of the alkyl chai