Solvatochromic materials

Solvation properties, of supercritical solvents, 14 80-81 Solvatochromic materials, 22 708t Solvatochromic probes, 26 853—855 Solvatochromic spectral shifts, 23 96 Solvatochromy, 20 517 Solvay, 7 641 Solvay process, 15 63... 

Owing to the original determination from uv—vis spectral solvatochromic shifts, 7T, B, and are called solvatochromic parameters. General rules for estimation of these variables have been proposed (258). Examples of individual parameter investigations are available (260,261). As previously mentioned, individual LEER—LSER studies are performed on related materials. A common method to link these individual studies to group contribution methods, and thereby expand the appHcabiUty, is by expansion of solvatochromic parameters to log—linear relationships, such as... 

Table I lists a variety of organic nonlinear materials which have appeared in the literature their relative powder efficiencies, absorption cutoffs and /3 values (if available) are also provided. These materials are "typical" only in that they represent results from the few classes of organic compounds investigated to date, yet they are instructive in that one learns which molecular properties may be important. A few caveats are in order to avoid misinterpretation of the data in Table I. Except for compound 10 (19) all the powder efficiency and cutoff data are from our own measurements. Powder measurements were performed on ungraded samples using the Nd YAG output at 1.06/t as fundamental since powder efficiency is a function of particle size distribution and a variety of other factors (3) these values are only semiquantitative. The cutoff values are the wavelengths for which 10-4M solutions in ethanol (unless otherwise indicated) have no absorbance. The cutoff values will be similar to those found in crystal state except where intermolecular charge transfer is important in the crystal or the molecule is solvatochromic, this latter effect being quite common for cyanine dyes such as...

Regioregular poly(3-alkylthiophene)s have received a lot of attention, especially because of their high electrical conductivities in the doped state, and because of their unusual solvatochromic and thermochromic behavior . Hence, a lot of research has been focused on clarifying the structure of these materials, both in the solid state and in solution. Today, it is agreed that supramolecular aggregation of polythiophene chains plays an important role in their physical properties. 

Chiral alcohols are useful starting materials for the synthesis of various biologically active compounds. The need for enantiomerically pure drugs and agrochemicals has increased in recent years [13]. Derivatives of enantiopure 1-phenylethanol are important chiral building blocks, which can be used as synthetic intermediates for the production of pharmaceuticals, fine-chemicals agrochemicals, and natural products. In particular (R)-1-phenylethanol is in widespread use as an ophthalmic preservative, an inhibitor of cholesterol intestinal adsorption, a solvatochromic dye, a fragrance, and so on. 

We have found that different polymeric matrices provide diverse response patterns of polymer-incorporated CdSe nanocrystals to vapors of different polarity. Such work promises to complement existing solvatochromic organic dye sensors with more photostable and reliable sensor materials. The stability of the sensor response pattern from 2.8 and 5.6-nm nanocrystals in PMMA film over more than 10 h of continuous exposure of the film to laser radiation is very attractive for diverse applications where continuous monitoring is needed. 

Poly thiophene [78] is a promising material for certain future electronic applications, due to its relatively high stability and processability in the substituted form [79-81]. Upon substitution, with e.g. alkyl side-chains [79, 80], polythiophene exhibit properties such as solvatochromism [82] and thermochromism [83]. Presently, a large variety of substituted polythiophenes with various band gaps exists (for example see Ref. [81]). 

The luminescent cyclometalated complex [Pt(C4ANAN)py]+ 39 immobilized in Nafion film has been observed to exhibit a solvatochromic shift in emission maximum from 530 to 650 nm upon immersion in ethanol but no effect was detected with aprotic organic solvents (Fig. 19) [41]. On the contrary, the emission of the [Pt(C4ANAN)]+ luminophore anchored on silica materials (MCM-41/-48 and silica gel) showed a blue shift from Tmax 665 to 550 nm upon exposure to pentane vapor but no shift was observed for ethanol vapor (Fig. 20). 

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