The IINS spectroscopy of amino acids: l-isoleucine

Abstract

Results of inelastic incoherent neutron scattering (IINS) supplemented by infrared (IR) and Raman scattering studies on normal and N-deuterated l-isoleucine in the energy transfer up to 800 cm −1 are reported. The IINS spectra of l-isoleucine show additional bands as compared to the spectra obtained by optical spectroscopic methods. In both, normal and d 3- l-isoleucine, extra bands correspond to out-of-plane γ(N–H⋯O) (518, 505, 250 cm −1) and γ(N–DO⋯O) (362 cm −1) hydrogen bond vibrations. Methyl and carboxyl groups vibrations are observed at 219, 228, 250, 281 cm −1 and 175, 543, 686, 749 cm −1 respectively.