Estimation of ground and excited state dipole moments of newly synthesized coumarin molecule by Solvatochromic shift method and Gaussian software

Received: 10/Apr/2019, Accepted: 19/Apr/2019, Online: 30/Apr/2019 Abstract: Absorption and fluorescence spectra of newly synthesized coumarin molecule namely 4-((3-methoxyphenoxy)methyl)-7-hydroxy-2H-chromen-2-one [3-MPHC] have been recorded at room temperature (300 K) in solvents of different polarities. The effects of solvents on the spectral properties are discussed. Using Lippert‟s, Bakshiev‟s and Kawski-Chamma-Viallet‟s equations the ground (μg) and excited state (μe) dipole moments were estimated. Variation of Stokes shift with the solvent dielectric constant along with refractive index was made use of to estimate dipole moments. Density Functional Theory (DFT) was studied using Gaussian software 16. It was observed that excited state dipole moment was higher than the ground state dipole moment. Further we have analyzed microscopic solvent polarity parameter.