High energy neutron inelastic scattering from H2 in C28Cs(H2)1.52

Neutron inelastic scattering from the intramolecular vibration of hydrogen at ca. 516 meV (4162 cm-1) has been observed for the first time using the system C28 CS(H2)1.52 at 4 K. There is some indication of fine structure and the Q dependence of the mean excitation energy gives an effective mass of the scattering particle of ca. 1.8 amu. The extrapolated excitation energy at zero momentum transfer is, within experimental error, the same as the gas phase value for H2, indicating little effect on the force constant of the electronegative environment. (author) 9 refs., 2 figs