MeOH mixed solvent

Linear correlations are observed between both log k, and log kr and the molar fraction of DMSO in DMSO-MeOH mixed solvents. As a consequence, the log K too is linearly correlated with the DMSO content. These correlations can be useful for predicting rate and equilibrium constant values in methanol by extrapolation whenever such values are too low for measurement in this solvent. 

The reduction of azides to amines proceeds in low yield under usual conditions, but it can be performed efficiently under phase-transfer conditions, using NaBH4 supported on an ion-exchange resin, or using a THF-MeOH mixed solvent (this last method is well suited only for aromatic azides). ... 

We reported that 3DOM Lai Sr, Fe03 (x = 0—0.2) was prepared using a mixed metal nitrate solution in mixed solvent of ethylene glycol and MeOH (entry 26) [41,42]. We reported that 3DOM LaFeOs prepared by our ethylene glycol-MeOH mixed solvent method showed higher catalytic activity for soot... 

Purified by repeated crystn from MeOH. It can also be purified by sublimation under vacuum. Purity can be checked by TLC using a mixed solvent (pet ether, diethyl ether, EtOH 10 10 1) on a silica gel plate. 

Ionic liquid [bmimJPFg can be used as a solvent in yeast reduction [21]. The reduction ofketones with immobilized baker s yeast (alginate) in a 100 10 2 [bmimjPFfi ionic liquid water MeOH mix affords chiral alcohols (Figure 8.28). 

The alkali-catalysed methanolysis of poly(2,2-bis(4-hydroxyphenyljpropane carbonate) (PC) in a mixture of methanol (MeOH) and toluene or dioxane was studied. The treatment of PC in meOH, with a catalytic amount of sodium hydroxide, yielded only 7% bisphenol A. Using a mixed solvent of MeOH and toluene completely depolymerised PC to give 96% free bisphenol A in solid form and dimethyl carbonate in solution. The eharaeteristies of the catalysis are discussed together with the pseudo-first rate kinetics of the depolymerisation. The reaetion eonditions were investigated to facilitate the reeyeling of PC plasties. 17 refs. 

The Eyring plot for the monophasic [Fe(CN)g] oxidation of spinach plasto-cyanin in 50 50 (v/v) MeOH-HjO mixed solvent over the extended temperature range 25 to —35 °C, pH 7.0, 1 = 0.10 M(NaCl), exhibits a marked downward curvature. Fig. 6 [105]. The rate constant at 25 °C of 1.04xl0 M" s compares with the value in Table 4 of 8.0 x 10 s . A plot of first-order... 

Despite earlier observations,624 625 ozonolysis of cyclic olefins in MeOH or in mixed solvents (ethers or esters and MeOH) followed by isomerization in the presence of Lindlar Pd and hydrogen does not give directly dicarboxylic acids. Instead, mainly the corresponding dialdehydes are formed.626 The best method of synthesis of dicarboxylic acids is ozonolysis of cycloalkenes in a mixture of acetic acid and formic acid followed by further oxidation with oxygen 626... 

Other hydrazine solutions using mixed solvent systems (MeOH-EtOH-THF) were susceptible to precipitate formation and did not display adequate swelling properties. 

Solvent. The following solvents that are transparent in the UV—Vis region are usually used water, MeOH, EtOH, acetonitrile, cyclohexane, and hexane. When a sample is weakly soluble in EtOH, a mixed solvent is used the sample is dissolved in a small amount of 1,4-dioxane and then diluted with EtOH. Spectrograde solvents should be used. 

A,A-Diethyl-4-nitroaniline is sensitive to the dipolarity/polarisability of the solvent. Since it shows positive solvatochromism, a decrease in the property increases the wave number of maximum absorption. It is possible to show that the wave numbers of maximum absorptions of pure solvents (Tj and increase in the order [bmim][Cl], [bmim][BF ], [bmim][PF ], MeOH, EtOEtOH and EtOH. The wave numbers of maximum absorptions of the mixed solvent S12 (T ) are close to... 

When water acts as a solvent, hydrogen bonds between water molecules are destroyed as water-solute interactions form the latter may be ion-dipole interactions (e.g. when NaCl dissolves) or new hydrogen bonds (e.g. when H2O and MeOH mix). 

This type of behaviour is not confined to polymorphs but may extend to pseudopolymorphic forms such as hydrates and solvates. A recent case of solvent-mediated phase transformation involved polymorphic and pseudopolymorphic forms of thiazole carboxylic acid [55], where the transformation is again sensitive to the composition of the mixed solvent. Three forms of the compound are known, an anhydrous form, a 0.5 hydrate, and a 1.5 hydrate. In 50-80% solutions (% = vol.% MeOH-H20), transformation of the 1.5 hydrate to the 0.5 hydrate was observed while transformation to the anhydrous form occurred in 85-100% solutions. No transformation occurred in 0-30% solutions. Detailed study of a solvent-mediated polymorphic transition has also been carried out for the antiulcerative agent cimetidine [56] for which seven polymorphic forms are known. An important feature of this study was the systematic use of seed crystals to induce crystallization at different supersaturation ratios. 

Trialkyl borohydrides such as Lithium Tri-s-butylborohydride and Potassium Tri-s-butylborohydride are superior reagents for the chemoselective 1,4-reduction of enones. On the other hand, 1,2-reduction can be obtained by using NaBHj in the mixed solvent MeOH-THF (1 9), or with NaBHj in combination with CeCH or other lanthanide salts. ... 

Two methods for preparation of ordered macroporous crystalline Ct203 have been reported. Chromium oxalate is soluble in H2O-EtOH solution, and the chromium oxalate solution infiltrates the voids of the templates. Solvents are removed by heating, and solid chromium oxalate is deposited in the voids and can be converted to Ct203 without melting. Another method is an in situ method. Cr(N03)3 is dissolved in EG-MeOH mixed solution, and the solution infiltrates the voids of the templates. By heating, EG reacts with Cr(N03)3 to form chromium oxalate derivatives in the voids by nitrate oxidation, and the chromium oxalate derivatives can be converted to Ct203 without melting. ... 

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