Inelastic neutron scattering spectroscopy of amino acids

Abstract

A combination of infrared, Raman and inelastic neutron scattering (INS) spectroscopies are used to provide complete vibrational spectra of several amino acids and dipeptides. The amino acids studied were glycine, alanine, glutamine, cysteine, methionine and phenylalanine and the dipeptides studied were Gly–Gln and Gly–Ala. The findings of this study have shown how the complementarity of infrared, Raman and INS spectroscopies can be exploited to provide complete vibrational spectra of amino acids and peptides. In particular, the strengths of INS spectroscopy are highlighted: the absence of selection rules, that hydrogenic motions are emphasised, the ready access to the low energy regime (<400 cm−1) and the straightforward calculation of intensities. In the future, it should be possible to apply this approach to the study of larger peptides as well as proteins.

INS, DFT and temperature dependent IR investigations of dynamical properties of low temperature phase of choline chloride

“…The methyl derivatives became the subject of our interest, since they are characterized by the high intensities of the CH 3 torsional modes. In the focal point reviews [27,28] the application and complementarities of infrared, Raman and INS spectroscopies in the investigation of dynamical properties of materials were presented. In the case of infra-red and Raman spectra the selection rules apply and moreover the intensities of respective bands can be very low.…”

Vibrational averaging of the chemical shift in crystalline α‐glycine

“…As discussed before,[47, 76] the periodic boundary conditions enable one to obtain realistic spectral profiles for the crystal. This can also be shown in Figure 1, where the calculated INS and Raman spectra are compared to experiment.…”

“…[30] We expect a frequency error of a few cm −1 both in the Raman and in the INS experiments because of the limited resolution of the spectrometers. [60, 76, 77]…”

Structure and spectroscopy of methionyl-methionine for aquaculture

“…Whilst methionine itself has been studied both structurally 12 – 14 and spectroscopically 15 – 21 , its dimer methionyl-methionine has been much less studied. Methionine contains a single asymmetric carbon, and thus exists as l and d enantiomers, whilst there are four possible stereoisomers (diastereoisomers) of methionyl-methionine: ll , ld , dl and dd , see Fig.…”