Infrared and Raman spectra of C6H6C6F6

The infrared and Raman spectra of C6H6C6F6 are analyzed. In the vibrational region, only minimal shifts are observed, compared to C6H6 and C6F6. For the low frequency lattice mode region, Raman spectra at 77 K and 20 K for C6H6C6F6 are different from those of the individual molecules. For C6D6C6F6, the lower frequency lattice modes exhibit no deuterium shifts, while the higher ones move to lower energies. These results are interpreted in terms of weak coupling between partners in the complex.