R.M. Melavanki

Solvent Effect on Absorption and Fluorescence Spectra of Three Biologically Active Carboxamides (C1, C2 and C3). Estimation of Ground and Excited State Dipole Moment from Solvatochromic Method Using Solvent Polarity Parameters

The absorption and fluorescence spectra of three Carboxamides namely (E)-2-(4-Chlorobenzylideneamino)-N-(2-chlorophenyl)-4, 5, 6, 7-tetrahydrobenzo[b]thiophene-3-carboxamide (C1), (E)-N-(3-Chlorophenyl)-2-(3, 4-dimethoxybenzylideneamino)-4, 5, 6, 7-tetrahydrobenzo[b]thiophene-3-carboxamide (C2) and (E)-N-(3-Chlorophenyl)-2-(3, 4, 5-trimethoxybenzylideneamino)-4, 5, 6, 7-tetrahydrobenzo[b]thiophene-3-carboxamide (C3) have been recorded at room temperature in solvents of different polarities using dielectric constant (ε) and refractive index (n). Experimental ground (μg) and excited (μe) state dipole moments are estimated by means of solvatochromic shift method and also the excited dipole moments are estimated in combination with ground state dipole moments. It was estimated that dipole moments of the excited state were higher than those of the ground state of all three molecules. Further, the changes in dipole moment (

Solvatochromic Effect on the Photophysical Properties of Two Coumarins

\Delta \mu

Estimation of ground and excited state dipole moments of aryl boronic acid derivative by solvatochromic shift method

) were calculated both from solvatochromic shift method and on the basis of microscopic empirical solvent polarity parameter (

Specific interactions of alcohols and non‐alcohols with a biologically active boronic acid derivative: a spectroscopic study

E_T^N

Effect of viscosity and dielectric constant variation on fractional fluorescence quenching analysis of coumarin dye in binary solvent mixtures

) and the values are compared.

Effect of Plasmonic Silver Nanoparticles’ Size on Photophysical Characteristics of 4-Aryloxymethyl Coumarins

The fluorescence quenching of 5, 6-benzo-4-azidomethyl coumarin (5BAMC) by aniline have been carried in different solvent mixtures of benzene (BN) and acetonitrile (AN) at room temperature by steady state fluorescence measurements. The quenching is found to be appreciable and a positive deviation from linearity was observed in the Stern-Volmer plot for the fluorophore in all the solvent mixtures. Various parameters for the quenching process have been determined using the extended S-V equation and have been found to be dependent on the solvent polarity. Further, with the use of finite sink approximation model, it is concluded that the bimolecular reactions quenching reactions are diffusion limited, and the distance parameter R′ and mutual diffusion coefficient D are estimated independently.