Spectroscopic and Molecular Docking Analysis of π-Acceptor Complexes with the Drug Barbital

Abstract

The drug barbital (Bar) has a strong sedative–hypnotic effect. The intermolecular charge transfer compounds associated with the chemical reactions between Bar and some π acceptors, such as 2,6-dibromoquinone-4-chloroimide (DBQ), tetracyanoquinodimethane (TCNQ), chloranil (CHL), and chloranilic acid (CLA), have been synthesized and isolated in solid state. The synthesized products have the molecular formulas (Bar–DBQ), (Bar–TCNQ), (Bar–CHL), and (Bar–CLA) with 1:1 stoichiometry based on Raman, IR, TG, 1H NMR, XRD, SEM, and UV-visible analysis techniques. Additionally, the comparative analysis of molecular docking between the donor reactant moiety, Bar, and its four CT complexes was conducted using two neurotransmitter receptors (dopamine and serotonin). The docking results obtained from AutoDockVina software were investigated by a molecular dynamics simulation technique with 100ns run. The molecular mechanisms behind receptor–ligand interactions were also looked into. The DFT computations were conducted using theory at the B3LYP/6-311G++ level. In addition, the HOMO LUMO electronic energy gap and the CT complex’s optimal geometry and molecule electrostatic potential were examined.

Keywords

• barbital
• charge transfer
• spectroscopy
• molecular docking
• density functional theory