Solvatochromic Study of Coumarin in Pure and Binary Solvents with Computational Insights into Dipole Moment, Reactivity, and Stabilization Energy.

Coumarin derivatives exhibit significant photophysical properties, making them valuable for various applications. This study investigates the solvatochromic properties of coumarin in pure and binary solvents, complemented by computational estimations of dipole moment, reactivity sites, and stabilization energy. Dipole moments were estimated using solvatochromic shift models, while computational techniques such as NBO and MEP were employed to analyse electronic properties. Results show that the excited-state dipole moment is significantly higher than the ground-state dipole moment, and fluorescence quantum yield correlates well with radiative and non-radiative decay parameters. NBO analysis confirms strong stabilization energy, while MEP mapping highlights key electrophilic and nucleophilic sites. These findings provide valuable insights into the electronic behaviour of coumarin, contributing to the development of optoelectronic materials.