IJSRP, Volume 2, Issue 12, December 2012 Edition [ISSN 2250-3153]
D. Nagaraja, N.R. Patil, Raviraj.A.Kusanur, H.D. Patil, R. M. Melavanki
The ground state (µg) and excited state (µe) dipole moments of two coumarin derivatives namely diethyl 2-acetamido-2-((3-oxo-3H-benzo[f]chromen-1-yl)methyl)malonate (2DAM) and ethyl2-((7-methyl-2-oxo-2H-chromen-4-yl)methyl)-3-oxobutanoate(2EMCO) were estimated in various solvents. The dipole moments were estimated from Lippert, Bakhshiev and Kawaski-Chamma-Viallet equations by using the variation of stokes shift with the solvent dielectric constant and refractive index. Ground state dipole moments were also calculated theoretically by DFT studies using Gaussian 03 software. It was observed that the excited state dipole moments calculated by solvatochromic shift method were greater than the ground state dipole moments indicating a substantial redistribution of the -electron densities in a more polar excited state for both the coumarin derivatives.