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

Abstract

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 (C(1)), (E)-N-(3-Chlorophenyl)-2-(3, 4-dimethoxybenzylideneamino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (C(2)) and (E)-N-(3-Chlorophenyl)-2-(3,4,5-trimethoxybenzylideneamino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (C(3)) have been recorded at room temperature in solvents of different polarities using dielectric constant (ε) and refractive index (n). Experimental ground (μ(g)) and excited (μ(e)) 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 (Δμ) were calculated both from solvatochromic shift method and on the basis of microscopic empirical solvent polarity parameter (E(N)(T)) and the values are compared.

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

“…In order to evaluate the ground and excited state dipole moments, we employed different solvent polarity functions like Δf, f 1 , f 2 and E N T , the values of which were obtained from the literature (16)(17)(18). volume of the molecule (29).…”

“…The values of OD and F int for the standard reference are given at the bottom of Table 3. The values of the relative quantum yield, calculated using equation (17), and the radiative and non-radiative decay rate constants (k r and k nr ), calculated using equations (18) and (19), are listed in Table 4. The values of the relative quantum yield, calculated using equation (17), and the radiative and non-radiative decay rate constants (k r and k nr ), calculated using equations (18) and (19), are listed in Table 4.…”

“…The excited state lifetimes (τ 0 ) of 4FMPBA in different solvents are also given in Table 3. The values of the relative quantum yield, calculated using equation (17), and the radiative and non-radiative decay rate constants (k r and k nr ), calculated using equations (18) and (19), are listed in Table 4. In protic solvents such as methanol, ethanol and heptanol, it was observed that the value of OD decreased with the increase in solvent viscosity (isopropanol is an exception), and the quantum yield increased slightly.…”

“…Although the photophysics and photochemistry of different heterocyclic molecules such as thiophenes, coumarin derivatives and quinine derivatives (16)(17)(18)(19) have been reported previously, the effect of solvent polarity on the photophysical properties of 4FMPBA has not been explored. In this work, the effect of solvent polarity on the wavenumbers of absorption and emission transition, relative quantum efficiency, radiative and non-radiative decay constants are reported.…”

Investigation of solvent effect on photophysical properties of some sulfonamides derivatives

“…∆µ values, calculated using Eq. (14), are given in Table 3. To explain the changes in dipole moments, the relation between Stokes shifts and the solvent polarity parameter was used.…”