Intermolecular Forces in Bioactive Resveratrol Complexes with Alcohols: A Study of Stability and Electronic Structure

Noncovalent interactions, particularly hydrogen bonding, play a pivotal role in determining the structural stability and functional properties of molecules, including bioactive compounds like resveratrol. This study focuses on the hydrogen-bonding behavior and other noncovalent interactions in gas-phase resveratrol-ethanol (EtOH) and resveratrol-methanol (MtOH) complexes, referred to as System 1 and System 2, respectively. These systems were optimized using the ωB97XD functional and cc-pVDZ basis set, providing a detailed picture of their stability and intermolecular interactions. By employing advanced methods such as Domain-Based Local Pair Natural Orbital Coupled Cluster (DLPNO–CCSD)(T) for energy decomposition, natural bond orbital (NBO) for charge analysis, atoms in molecule (AIM) for electron density topology, and noncovalent interaction (NCI) techniques, we decompose interaction energies into meaningful components like electrostatic, dispersion, and exchange-repulsion. The findings indicate that, while hydrogen bonding contributes to the stability of these complexes, London dispersion and other attractive interactions are substantial factors as well. The resveratrol-EtOH and resveratrol-MtOH systems demonstrate a robust electronic environment with significant contributions from various intermolecular forces, underscoring the importance of noncovalent interactions in stabilizing bioactive compounds. This study adds to our understanding of molecular interactions in resveratrol complexes, with potential implications for medicinal chemistry and material science, particularly where solvation effects are critical.