An investigation on spectroscopic, wavefunction dependent reactivity, docking and anti-Covid-19 ability of flupentixol dihydrochloride: DFT and MD simulations at different temperatures.

[Display omitted] • Intermolecular hydrogen bonding due to O 1 -H 1B ...Cl 1 (2.266 Å), N 1 -H 1A ...Cl 1 (2.102 Å) and C 9 -H 9A ...F 3B (2.655 Å) • Electrons were resonated on the aromatic ring systems. • Surface view of FDC with SARS-CoV-2 main protease shows that FDC is well accommodated within in the binding pocket. • Radius of gyration signifies the ligands binding compel the proteins to become more compact and less flexible. A detailed vibrational analysis of flupentixol dihydrochloride (FDC) is performed by Density Functional Theory (DFT) calculations. Wavefunction reactivity properties and Atoms In Molecules (AIM) analysis are also performed. There is enormous O 1 -H 1B ...Cl 1 , N 1 -H 1A ...Cl 1 and C 9 -H 9A ...F 3B intermolecular hydrogen bonding in FDC. Electrons were resonated on the aromatic rings without any interference with aliphatic moiety of both highest occupied molecular orbital (HOMO) and in least unoccupied molecular orbital (LUMO) which is due to participation of fluorine atom intermolecular hydrogen bonding with adjacent C–H. The electron localization function (ELF) shows under populated N-C single bonds of ring A owing to the strong electron withdrawing effect of nitrogen atoms. SARS-CoV-2 main protease with FDC had energy −80 kcal/mol. With the help of molecular dynamics (MD), radial distribution functions (RDF) are calculated to identify the most critical interaction with water molecules. [ABSTRACT FROM AUTHOR]