THE ROTAMERIZATION OF CONFORMERS OF GLYCINE ISOLATED IN INERT-GAS MATRICES - AN INFRARED SPECTROSCOPIC STUDY

The infrared spectra of glycine isolated in Ne, Ar and Kr matrices have been measured. The matrix-isolated glycine is shown to be in the molecular form. The spectral manifestations, both conformational and site splitting, are separated. Three different conformers of glycine have been identified experimentally for the first time. It is shown that during the deposition of the samples the substrate temperature must be lowered to 13 K - this is a decisive factor permitting fixation of a complete set of glycine conformers in an inert matrix. The relative energies of the three glycine conformers are estimated to be 0, 1.3-1.6 and 0.9-1.5 kcal/mol.