Ultraviolet irradiation of glycine in presence of pyrite as a model of chemical evolution: an experimental and molecular modelling approach

Abstract

AbstractIn this work, the molecular interaction of the amino acid glycine and the mineral pyrite was performed to gain insight into the potential role of the mineral as a precursor of chemical complexity in the presence of ultraviolet (UV) radiation. Glycine samples were self-assembled on pyrite with and without exposure to UV radiation and subsequently characterized by scanning electron microscopy, infrared spectroscopy (with the second-derivative method), and AM1 and PM3 semi-empirical molecular computational simulations. In this work, our molecular modelling results suggest that pyrite acts as a template for self-assembly of glycine, and it is a potential catalyst for the glycine dimerization of relevance in interstellar space and ancient Earth conditions. A change in the structural complexity of glycine from the α to its γ polymorph when irradiated with UV radiation can be a condition for chemical evolution towards living forms.