Ethanol, solvent

There is very little published information on the UV spectra of 1,2-benzisothiazoles, though more data are available on the 2,1-isomers. The spectra are complex with as many as six maxima above 200 nm. Representative wavelengths of maxima are collected in Table 12. In all cases the most intense bands (e > 15 000) are those at short wavelengths, but all the bands indicated in the table have molar absorptivities greater than 4000, except those of 3-amino-2,l-benzisothiazole. Saccharin absorbs weakly at 350 nm and 277 nm, with intense bands below 230 nm (ethanol solvent) (82UP41700>. It exists as the anion except in acid solutions. The UV spectra of cations formed from 3-amino-2,l-benzisothiazole are discussed in (69CB1961>. Further applications of UV spectroscopy in studying tautomeric... 

The rate of hydrogen (or deuterium) uptake with homogeneous catalysts is usually faster in benzene-alcohol (methanol or ethanol) solvent systems or in acetone than in tetrahydrofuran or in benzene alone. Whereas... 

The amount of diketone 9 formed during the reaction could be enhanced by using no solvent or ethanol solvent in place of benzene solvent. The use of... 

The reaction between the pyrrolidine enamine of butyraldehyde (52) and )3-nitrostyrene (53) provides cyclobutane adduct 54 quantitatively in either petroleum ether or acetonitrile solvent, but in the more polar ethanol solvent a 2 1 condensation product occurred. The structure of the product was shown to be 55 (57). 

In saturation of ethyl p-tolyl ether in ethanol solvent, hydrogenolysis rose with metal in the order Pd < Ru Rh < Ir < Pi ( 7). The various complex factors contributing to this ordering are discussed at length in this reference. 

These values were derived from data obtained in ethanol solvent (see p. 86 in Reference 50a). 

The data in Table 2 show that with CD concentration around of 10 4 M, the addition of ATA resulted in slight increase in the reaction rate, but a decrease in the ee24o values was observed, with eemax unchanged. By adding ATA, at [CD] = 10 5 M, beside increased activity shown by ki ami k2 about 25 % increase of ee value was observed. Different from the observation in the hydrogenation of Etpy, this ATA effect was observed in ethanol solvent. This may be explained as... 

The hydroxyl-terminated polymer was then added to the dispersion and the mixture allowed to stand for 24 hr to achieve adsorption equilibrium. Further n-heptane was then added to give a 4 1 (by volume) n-heptane ethanol solvent composition, and the sample... 

Groups containing n electrons and capable of undergoing 7T —> 7T transitions e.g. CH2 = CH2 which has one chromophore, having xmax 1850 in ethanol solvent. 

The homogeneous solvolysis of this substrate in aqueous ethanolic solvents can be monitored by the change in conductance as HCl is produced. Initial studies of the reaction in aqueous ethanol as solvent at 25 °C using a cleaning bath (45 kHz) revealed modest rate enhancements (up to about 2-fold) with the larger values being obtained in the more alcoholic media [37]. Similar results were found for the solvo-lyses in aqueous propan-2-ol and 2-methylpropan-2-ol. More substantial rate enhancements were obtained in the more ethanolic media and at lower temperature [38,39]. Detailed studies of the aqueous ethanol system led to the following main conclusions ... 

However, the difference was observed in the LCST change of polymer mixture depending on the preparation method of polyDMAEMA. As presented previously, polyDMAEMA can be prepared in water containing APS as an initiator and TEMED as an accelerator or water/ethanol solvent mixture containing AIBN as an initiator. PolyDMAEMA prepared in the... 

Poly DMAEMA prepared in water/ethanol solvent mixture 18.36 16.49 13.63 3.28 5.49 2.95... 

In the Claisen-Schmidt condensation at the same temperature and with ethanol solvent present, lower yields of a-enones were observed. The best yield corresponds to condensation of the most reactive furfural with acetophenone, giving 95% a-enone after 1 h in a batch reactor. A comparison of the results characterizing the two reactions led to the conclusion that the W-H reaction provides the more efficient and selective synthesis of a-enones however, the CS condensation provides the more economic approach. 

Fig. 14 photographs of HNBR/SP nanocomposites in a chloroform/MEK and b chloroform/ ethanol solvent combinations... 

Figure 19 shows the rate-constant curves for the reaction of [Co(IIIXen)2LCl]2+ (L = PVMI or N-ethylimidazole(NEI)) with Fe-edta2- in H20-alcohol mixed solvents. An increase in the alcohol content brings about the enhancement of the reactivity of the Co(III) complex however, maxima and minima appeared in the reaction between PVMI-Co(ni) and Fe-edta2-. The viscosity behavior of the PVMI-Co(III) complex solution is also shown as a function of ethanol concentration in Fig. 19. There is good correlation between the reactivity curve and the viscosity curve, with the maximum (minimum) point of the reactivity precisely coincident with the minimum (maximum) point of the viscosity. The decrease in viscosity reflects a contraction in the PVMI chain caused by the suppression of charge dissociation of the Co(III) complexes or of electrostatic repulsion due to the nonpolar ethanol solvent. At intermediate ethanol concentration (5—7 mol%) the hydro-...

Fig. 3. shows the TEM images of various Ti-MCM-41 materials. Ti-MCM-41 which was prepared from the acidic mixture in ethanol solvent exhibited a fully disordered mesopore structure. But the regular pore system was obtained by using a methanol solvent. 

Fig.3. TEM images of Ti-MCM-41 obtained by the solvent evaporation method. (A) C22TMACl/Ethanol solvent (B) C22TMACl/methanol solvent...

Jada [27] followed the acid catalyzed hydrolysis of TEOS by NMR. He generated the water in situ by the reaction of acetic acid with the ethanol solvent. He was able to follow the changes in the concentrations of the CH2 and CH, of the TEOS and the OH of the ethanol. These changes led him to the conclusion... 

A somewhat similar oxidation of terminal alkenes to methyl ketone and alcohol by 02 in the presence of Co(salMDPT) [salMDPT = bis(salicylideneiminopropyl)methylamine] and in ethanol solvent has recently been reported by Drago and coworkers (equation 244).560 Only terminal alkenes were found to be reactive with this catalytic system. The reaction is alcohol dependent and occurs in ethanol and methanol but not in t-butyl or isopropyl alcohols. The alcohol is concomitantly oxidized during the reaction, and may act as a coreducing agent and/or favor the formation of cobalt hydride. This oxidation might occur according to the mechanism of equation (243). 

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