Raman scattering intensities of the C=C stretching vibrations were measured for about sixty compounds of several types. The intensities were determined relative to that of the C=C stretching vibration of tetrachloroethylene. It was shown that for alkyl-substituted ethylenes, the intensities are constant for the compounds with the same types of substitutions. However, they increased in an orderly fashion with the numbers of substituents. For the diene compounds, the intensities were enhanced markedly when the two C=C groups are in the conjugation, but in the case of no conjugation, they were about twice as large as those of the substituted ethylenes, that is, the additivity of intensities was realized. Such additivity was proved also for some alicyclic compounds containing two double bonds. The interesting fact is that in the case of acrylates and methacrylates in which the C=C group is assumed to be in the conjugation with the C=0 group, the influence of this conjugation was not apparent, though the intensities of the corresponding C=0 stretching increased remarkably. It was concluded that the obtained results give an useful guide to the group type analysis by Raman spectrometry.
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