Computational Insights into the Electronic Structure of 3‐Phenyl Coumarins

Abstract The structural and geometry parameters of 3‐phenyl coumarins were studied utilizing DFT/BL3YP/6‐311++G(d,p) approach. The frontier molecular orbital (FMO) analysis was implemented to understand the nature of intramolecular charge transfer (ICT) within the molecules. The analysis also computes the global descriptors to account for their electronic and optical properties. The electrostatic potential surfaces (ESP) and Mulliken charges on their optimized geometries reveal charge distribution across the molecular framework. UV–Visible absorption spectra of molecules were obtained from TDDFT computations to identify the different peaks and corresponding electronic transitions. IR spectra have been elucidated to examine the vibrational frequencies of different bonds. Hirshfeld surface (HS) analysis and 2D fingerprint plots investigated the type of interactions in the molecule and interpret H⋯H interactions as the prominent one. The ESP maps confirmed O 2 atom and hydrogen atom of coumarins as electrophilic and nucleophilic centers, respectively. The global descriptors ( η , χ , μ p , and ω ) calculated from FMO analysis labeled molecules as strong electrophiles with high chemical reactivity and stability. The results validated the computed molecular properties relationship with the chemical substitutions. The present analysis fortifies the stability of 3‐phenyl coumarins and reflects amplified ICT in polar solvents proposing their suitability in various energy‐modulated applications.