Low Temperature Raman Spectra of Dibenzyl; Comparison with Biphenyl and Paraterphenyl

Abstract

The Raman spectra of crystal dibenzyl have been recorded from 293 down to 10 K. No typical temperature dependence which usually accompanies phase transitions has been observed in frequencies, intensities or background. A comparison is made with biphenyl and paraterphenyl whose evolution of Raman spectra with the temperature looks similar. The very broad bands observed at room temperature result from the superposition of the different modes which appear well separated at 10 K. This behavior is consistent with the large atomic thermal motion observed by X-ray analysis. Vibrational frequencies have been calculated using the intermolecular potential of the atom-atom type in the rigid phenyl approximation and compared with experimental data.