Molecular Recognition of Dopamine–Diazepam Biomolecular Complex for Implication in Anxiety Disorders Using the DFT and Molecular Docking Methods

ABSTRACT The present work focuses on the Molecular recognition of the dopamine–diazepam biomolecular complex in anxiety disorders using computational methods. The monomers and the neurotransmitter (dopamine)–diazepam biomolecular complex are optimized, and molecular properties are calculated using density functional theory (DFT) at the B3LYP/6‐311++G(d,p) level of theory. Furthermore, IEFPCM (water as solvent) and counterpoise correction for BSSE models have also been adopted to compare and analyze the molecular properties of the complex. Noncovalent interaction (NCI) analysis confirms the presence of intermolecular hydrogen bonding. Molecular docking using the AutoDock tool indicates a negative binding energy of −7.75 kcal/mol for the dopamine–diazepam biomolecular complex (IEFPCM calculation), suggesting a favorable binding affinity with protein 4M48. The intermolecular charge transfer processes, such as n→ σ, n→ π, and σ→ σ, are detected, indicating delocalization that results in increased reactive interactions, ultimately contributing to active participation in the formation of the biomolecular complex. The π–π conjugation is shown by π*(C 5 –C 6 ) →π*(C 3 –C 4 ) with stabilization energies of 293.52 kcal/mol (IEFPCM), 183.78 kcal/mol (counterpoise correction for BSSE), and 239.75 kcal/mol (DFT‐D3), in which the highest π*→π* is displayed by the IEFPCM calculation. UV analysis also confirms the π→ π* electronic transition behavior.