the synthesis and properties of new monoazo dyes derived from the diazonium salts of paminobenzoic acid, 3-trifluoromethyl aniline , 4-trifluoromethyl aniline are considered .theprepared compounds were characterized by uv-visible , ft-ir and h nmr spectroscopictechniques . the effect of varying solvent upon the absorption ability of p-amino benzoic acidcoupled with 4,4 —diethyl aniline , anilin...

Several theoretical and experimental studies have shown that organic dyes may show solvatochromic reversal in the visible region with respect to the solvent polarity. This controversial non-monotonic behavior is still not well understood. This has been analyzed here using the merocyanine of Brooker as the working example. Sometimes the solvatochromic reversal is attributed to self-aggregation.[...

The synthesis of 5-arylazosubstituted bithiophenes and their UV-visible, solvatochromic and nonlinear optical properties (NLO) are described. In agreement with the solvatochromic data and also with the second-order molecular NLO characterization, the new donor-acceptor systems could find application as suitable solvatochromic probes and also as new NLO materials.

of various physicochemical and spectroscopic measurements using various indicator compounds. 1–6 Especially, three parameters, dielectric constant, DC, donor number, DN, and acceptor number, AN serve as fundamental and extensive set for applications. However, it is not easy to directly derive these parameters by means of the original measurement method. It is expected that they can be predicted...

As they have been designed to undergo colorimetric changes that are dependent on the polarity of solvents, the majority of conventional solvatochromic molecule based sensor systems inevitably display broad overlaps in their absorption and emission bands. As a result, colorimetric differentiation of solvents of similar polarity has been extremely difficult. Here we present a tailor-made colorime...

This review compiles positively and negatively solvatochromic compounds which have been used to establish empirical scales of solvent polarity by means of UV/vis/near-IR spectroscopic measurements in solution-with particular emphasis on the E ~ ( 3 0 ) scale derived from negatively solvatochromic pyridinium N-phenolate betaine dyes. This requires a short discussion of the concept of solvent pol...

The compound 2-[(1E)-2-(1H-pyrrol-2-yl)ethenyl]-quinoxaline (PQX) is a promising fluorescent chromophore for the estimation of protein binding site polarity, due to its full-color solvatochromic fluorescence. A linear relationship was obtained between the peak emission wavenumber and E(T)(N) (normalized solvent polarity). The BSA binding site polarity was estimated from the solvatochromic plot.

Monte Carlo simulation and quantum mechanics calculations based on the INDO/CIS and TD-DFT methods were utilized to study the solvatochromic shift of benzophenone when changing the environment from normal water to supercritical (P = 340.2 atm and T = 673 K) condition. Solute polarization increases the dipole moment of benzophenone, compared to gas phase, by 88 and 35% in normal and supercritica...

Solvatochromic behaviours of triazine substituted dyes were evaluated using a novel approach derived from the red shift index (RsI) and associated solvation energy (ASE). These parameters used to describe trends dye–solvent interactions based on their polarity changes. The concept demonstrates effect substituent changes scaffold induced solvent as solvated go through HOMO–LUMO (highest occupied...

In N-(2,5-di-tert-butylphenyl)-9-pyrrolidinoperylene-3,4-dicarboximide (5PI) the absorption and emission spectra display large solvatochromic shifts, but, remarkably, the Stokes shift is practically independent of solvent polarity. This unique behavior is caused by the extraordinarily large ground state dipole moment of 5PI, which further increases upon increasing solvent polarity, while the ex...