Structural, spectroscopic, electronic, Hirshfeld, QTAIM and biological predications of a hybrid 2,6-dichloropurine compound: A detailed density functional theoretical study

Abstract

Extensive research into the optimized structure, spectroscopic and biological properties of 2,6-dichloropurine (6DCP) was conducted using IR/Raman and NMR techniques, as well as theoretically using the DFT approach with B3LYP, CAM-B3LYP, and PBEPBE function levels at 6-311++G(d, p) basis set. The computational results from DFT approaches such as geometrical, IR/Raman and NMR spectra were compared with the experimental results. All our theoretical calculations were in good agreement with observed data. The electronic HOMO-LUMO, H-bonding and strong conjugative interactions across different molecular entities are discussed to reveal the accompanying pharmaceutical intermediate. The molecular properties such as chemical reactivity descriptors, mapped ESP, dipole moment, mean polarizability, and first order hyperpolarizability of the title molecule were calculated by quantum mechanical calculations. The high value of the electronic dipole moment and polarizability estimate for the 6DCP molecule may improve its biological activity. The NBO study has enabled researchers to investigate hyper-conjugate interactions, intramolecular bonding, and strong H-bonding interactions. Strong H-bonding interaction energies of 120.47 kcal/mol have been performed at the DFT/PBEPBE level.