Structural and spectral properties of astronomical complex organic molecules: 1:1:1 glycine-X-Y and Y-glycine-X

Abstract

Current research to understand astrochemistry and astrobiology with regard to the weakly bound astronomical complexes including amino acids in the Inter-Stellar Medium (ISM), comets and meteorites at molecular level are flourishing and many new findings are emerging rapidly. Modern experimental techniques and computational investigations assisted by quantum chemical analysis are playing key role towards exploring the evolution of many molecular complexes in astrochemical environment and planetary atmospheres by affecting their stability as well as their structural and spectral properties. The present work deals with weekly bound complexes of glycine with small molecules like water, ammonia and HF as 1:1:1 Glycine-X-Y and Y-Glycine-X. The affects that influence the complexation, mainly involve through non-covalent interactions with these small molecules have been explored, based on various properties of the red shifted hydrogen bonds of the type: OHO, NHO, FHO, OHN and carbon-cantered blue shifted hydrogen bonds, CHO type, for all the stable complexes of 1:1:1 Glycine-X-Y and Y-Glycine-X with respect to their structural properties and spectral characterization. The computed Ray's asymmetry parameter, κ values for the investigated 1:1:1 Glycine-X-Y and Y-Glycine-X complexes are found to be negative and predicted as prolate-type asymmetric rotor. The computed rotational constants and IR spectra of these different complexes may assist in the interpretation and analysis of observational data and the data obtained in laboratory experiments. The possibilities of formation of such molecular complexes in the interstellar space may provide a direction to explore new possibilities.