Lattice vibrations of crystalline imidazole and 15N and D substituted analogs

Raman spectra of single crystals and polycrystals of imidazole and 15N and D substituted analogs have been measured. All the active Raman bands have been observed, at 100 K, and their isotopic shifts are discussed with a view to defining unambiguously the corresponding rotational or translational modes for several bands. More detailed assignments have also been deduced from normal coordinate calculations.