The vibrational spectroscopy of C60H36: An experimental and theoretical study Original Research Article

Several samples of C60H36 have been prepared by the transfer hydrogenation method and studied by infrared and Raman spectroscopy. The results are compared with published infrared spectra of C60H36 samples synthesized by other techniques such as high pressure hydrogenation and zinc reduction of C60. Raman spectra of C60H36 have not previously been reported. Based on previous data in the literature, five isomers of low-energy were selected for semiempirical quantum chemical calculations. They are one each of S6, T and Th symmetry and two isomers of D3d symmetry. The calculations predict that very few IR lines will be coincident with Raman bands, even in the case of the T isomer for which t symmetry vibrations can be both infrared and Raman active, and for which the few coincident lines should be extremely weak. The interplay between theory and experiment places some strong constraints on the possible symmetries and structures of the various samples of the C60H36 molecule. The results indicate that each of two samples prepared by transfer hydrogenation contains a mixture of two principal isomers, of D3d and S6 symmetries, the former being the major component in one, and the latter in the other, sample. The analysis also confirms a D3d isomer as being the major component of a sample of C60H36 prepared by high pressure hydrogenation and proposes the S6 isomer as the major component of a sample prepared by zinc reduction of C60 in aromatic solvents.