The 3, 5, 6, and 7 THz resonances of α-glycine

T J Sanders; J L Allen; R Plathe; J Horvat; R A Lewis

doi:10.1016/j.saa.2021.119544

The 3, 5, 6, and 7 THz resonances of α-glycine

Spectrochim Acta A Mol Biomol Spectrosc. 2021 May 15:253:119544. doi: 10.1016/j.saa.2021.119544. Epub 2021 Feb 9.

Authors

T J Sanders¹, J L Allen², R Plathe³, J Horvat², R A Lewis²

Affiliations

¹ Institute for Superconducting and Electronic Materials and School of Physics, University of Wollongong, NSW 2522, Australia. Electronic address: tjs804@uowmail.edu.au.
² Institute for Superconducting and Electronic Materials and School of Physics, University of Wollongong, NSW 2522, Australia.
³ Australian Synchrotron, Australian Nuclear Science and Technology Organisation, 800 Blackburn Rd Clayton, VIC 3168, Australia.

PMID: 33631628
DOI: 10.1016/j.saa.2021.119544

Abstract

Using an optically thin single crystal sample, mounted in a cryostat permitting cooling to 6 K, and a synchrotron as a bright light source, exceptionally well defined absorption spectra of well-characterised α-glycine have been obtained in the spectral range 2.5-7.5 THz (approximately 80-240 cm^-1). Four separate resonances have been observed, respectively at 93, 152, 188, and 223 cm^-1 at the lowest temperature. Each reduces in frequency (redshifts) as temperature increases. The origin of this observed behaviour is attributed to a phonon-mediated anharmonicity in the crystal potential.

Keywords: -glycine; Amino acid; Redshift; Synchrotron; Terahertz.