Study by DFT of the functionalization of amylose/amylopectin with glycerin monoacetate: Characterization by FTIR, electronic and adsorption properties

Based on the Density Functional Theory (DFT) calculations, in this work is studied the electronic and vi-brational characterization of different molecular complexes formed by a molecule of glycerol monoacetate (or monoacetin) and short chains of the starch polymer (amylose or amylopectin). The computational cal-culations were performed using the B3LYP functional and the 6-31G basis set. All systems studied have a neutral charge and a singlet multiplicity. In this work we propose two different forms of interaction: molecules that interact laterally (Models 1.1 and 2.1) and linearly (Models 1.2 and 2.2). All the com-plexes showed to be energetically stable, whose adsorption processes are exothermic. The analysis of the thermodynamic functions and the global quantum-molecular descriptors indicate that the complex formed between monoacetin and amylose tetramer (Model 2.1) is the most stable, with a spontaneous chemisorption process. FT-IR theoretical spectra of these molecular complexes are obtained, which may be used in the future studies as theoretical identifiers.(c) 2022 Elsevier B.V. All rights reserved.