Effect of solvents on photophysical properties and quenching of 2‐{[3‐(1H‐benzimidazole‐2‐yl) phenyl] carbonoimidoyl}phenol

Abstract

The effect of solvents of varying polarity on the absorption and fluorescence emission of the Schiff base, 2-{[3-(1H-benzimidazole-2-yl) phenyl]carbonoimidoyl}phenol, was studied using Lippert-Mataga bulk polarity function, Reichardt's microscopic solvent polarity parameter and Kamlet's multiple linear regression approach. The spectral properties follow Reichardt's microscopic solvent polarity parameter better than Lippert-Mataga bulk polarity parameter, indicating the presence of both general solute-solvent interactions and specific interactions. Catalan's multiple linear regression approach indicates the major role of solvent polarizability/dipolarity influence compared with solvent acidity or basicity. The solvatochromic effect was utilized to calculate the dipole moments of ground and excited states of the Schiff base using different methods. Bathochromic shift in the emission spectrum and the increase in dipole moment in the excited state signifies the intramolecular charge transfer character in the emitting singlet state. Fluorescence quenching by aniline was also studied in 1,4-dioxane and n-butanol, and the results were analyzed using sphere of action static quenching and finite sink approximation models.

Effects of Intrinsic Local Fields on Molecular Fluorescence and Energy Transfer: Dipole Mechanisms and Surface Potentials

“…Although vector difference features in the excited and ground states feature in work by Suppan [24], it is relatively rare that the theory is used to support vector determinations -and clearly if the ground and excited state dipoles differ in orientation then the magnitude of  is not simply the difference in values eg   . A good example of securing information on the relative orientations as well as values is a recent analysis of Suman et al [25].…”

Benzothiazole-Based Bis-azo Cationic Fluorescent Dyes with Extended Conjugated Systems: Synthesis and Properties

“…Each of dyes 5a-p was excited at a unique wavelength within range of 272-315 nm and showed fluorescence emission at a corresponding wavelength within range of 380-494 nm (Figure 1). Stokes shift ( A -F ), the important characteristic for fluorescent compounds, 42 has been evaluated for the selected bischromophoric dyes.…”

“…Solvatochromism refers to an ability of a chemical compound to change the color due to change in solvent polarity and solvatochromic dye molecules have recently attracted much attention owing to their application as probes for the determination of solvent polarity [14,[42][43][44][45].…”

“…Solvatochromism lies at the basis of interaction between solvent and molecules' functional groups such as dipole moment change upon excitation from ground to excited state; therefore solvent-dependent spectral changes of solvatochromic dyes provide a precise sensor of changes in the surrounding environment [14,[42][43][44][45]. Solvatochromic behavior of cationic dyes 5 with symmetrical (5a-h) and asymmetrical (5i-p) structures were studied in different common solvents varying in polarity.…”

“…Generally, Lippert-Mataga equation (4 and 5) describe how the stokes shift changes as a function of solvent properties [42][43][44][45]…”