Optical and Neutron Inelastic Scattering Study of 2-Methylnorbornanes

Article abstract of DOI:10.1021/j100252a010

We have measured the infrared, Raman, and neutron vibrational spectra of the 2-methylnorbornanes with a CH3 or CD3 methyl group in the exo or endo position.A normal coordinate analysis has been carried out.The torsional modes of the methyl group are assigned at 240 and 235 cm^-1 for the hydrogenated exo and endo isomers, respectively.The corresponding barrier is 15.2 +/- 0.2 kJ mol^-1.The calculated neutron intensities are in good agreement with the experimental data.The frequencies are used for the determination of the thermodynamic contribution to the standard free energy difference.