Vibrational Spectra and Conformational Analysis of Isomers of 1,3-Diphenyl Propane and 4-(3-Phenyl Propyl)Pyridine

The Raman and infrared spectra of 1,3-diphenyl propane and 4-(3-phenyl propyl)pyridine were recorded in the liquid state, at room temperature, in the range from 4000 cm−1 to 200 cm−1. The vibrational assignments allowed us to identify the presence of three staggered conformers, AA, AG and GG. No evidence was found of existence of the GG1 conformer with the two parallel phenyl (or pyridil) ring groups. These results have been used to correlate the normal modes from these molecules with those from the polystyrene and polyvinylpyridine.