heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by pt/a1203, was carried out in thirteenvarious solvents (four alcoholic solvents, six aprotic polar solvents and three non polar solvents) at 25 °c.single-parameter correlations of logk vs. normalized polarity parameter (etn), hydrogen-bond acceptorbasicity (p), hydrogen-bond donor acidity (a) and dipolarity/polarizibility (it*) d...

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...

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...

The solvation properties of some room-temperature ionic liquids consisting of imidazolium cations and various anions were examined by means of the high-pressure spectroscopy with solvatochromic probes. We measured the pressure dependence of KamletTaft solvatochromic parameters (π∗, β) and microviscosity (η). It was found that π∗ and β were not so sensitive to the types of imidazolium cations an...

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...

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.

the solvatochromism of fluoresceine and its derivatives was studied in solvents of different hydrogen bond donor (hbd), hydrogen bond acceptor (hba), donor number (dn) and acceptor number (an) by their uv-vis spectra. results showed that position, intensity and shape of absorption bands change with type of solvent. these changes can be rationalized by solvatochromic parameters such as α, β, et ...

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...