Vibrational properties of novel diacetylenic monomers
The frequency and intensity of the infrared and Raman CC modes have been investigated for a large number of molecules. A series of symmetrical and asymmetrical substituted diacetylenic monomers having the carbazole group attached directly or indirectly to the diacetylenic backbone have been studied in their microcrystalline or liquid state. A qualitative assignment has been proposed and particular attention has been given to those systems for which a peculiar behaviour of the infrared and Raman intensities has been observed. This behaviour is found when the diacetylenic skeleton is directly attached to either the 9H-carbazolyl or triethylsilyl group.