Hydrogen bonding interactions between α-, β-glucose, and methacrylic acid

Intermolecular interactions between alpha-, beta-glucose, and methacrylic acid (MAA) have been investigated. Twenty-two possible conformations have been optimized at the DFT(B3LYP) level of theory with the 6-31G(d) basis set. The geometrical parameters for the most stable configurations of hydrogen bonding sites in the optimized systems have been determined. The binding energies Delta E-bind have been calculated at the MP2/6-311?? G(d, p) level of approximation taking into account the basis set superposition error (BSSE) and the zero-point vibrational energies corrections. Results indicate that the most stabilized complexes form hydrogen bonds either through carboxylic and hemiacetal oxygen atoms acting as proton acceptors. Both, a-and beta-anomers are studied in the pyranose six-membered ring. In all complexes, the nuclear quadrupole coupling constants (v) for O-17 nuclei were obtained about 10.0 MHz, while for the H-2 atoms they vary from approximate to 200.0 to approximate to 350.0 kHz.