Super solvent

Enzyme active sites, 136,148, 225. See also Protein active sites in carbonic anhydrase, 197-199 in chymotrypsin, 173 in lysozyme, 153, 157 nonpolar (hypothetical site), 211-214 SNase, 189-190,190 steric forces in, 155-158, 209-211, 225 in subtilisin, 173 viewed as super solvents, 227 Enzyme cofactors calcium ... 

Super Solvents for TATB (solubility > 20% (w/v)) Concentrated sulfuric acid Chlorosulfomc acid Fluorosulfonic acid Trifluoromethanesulfonic acid... 

They act as super solvents of drug. They can solubilize hydrophilic and lipophilic drugs including drugs that are relatively insoluble in both aqueous and hydrophobic solvents. This is due to the existence of microdomains of different polarity within the same singlephase solution. 

Another class of solvents is the so-called super-solvents—typically dipolar aprotic solvents that are capable of dissolving a large amount of the organic material in coal (Stiller et al 1981). Supersolvents can dissolve many substances, both polar and nonpolar. 

Modem chemists continue to expand the boundaries of known materials. They have discovered plastics that conduct electricity like metals and materials that look solid, but are so porous they are almost as light as air. Now chemists have produced room-temperature ionic liquids (Figure 9.4). Most of these are clear, well-behaved substances that look and pour much like water, and like water their strength is as solvents (liquids that dissolve other substances). In fact, they promise to be super solvents. Given a material—an organic substance, a plastic, or even a rock—researchers believe you will be able to find an ionic liquid that is capable of dissolving it ... 

This procedure can be applied to most P2P mixes but is especially effective on the methods to follow. However, in super clean methods, such as the PdCl2 below, where lots of isosafrole is produced, the iso byproduct can interfere with crystal formation. Someone-Who-ls-Not-Strike once found that when an appreciable amount of isosafrole was formed to the detriment of MD-P2P, the oil screwed up the crystal matrix disallowing it to form. Confused, the chemist tried to rescue the uncrystallized oil from the aqueous solution by extracting out the oil to try other things. But when the solvent hit the solution, the P2P crystallized out. Go figure The... 

Acid-cataly2ed hydroxylation of naphthalene with 90% hydrogen peroxide gives either 1-naphthol or 2-naphthiol at a 98% yield, depending on the acidity of the system and the solvent used. In anhydrous hydrogen fluoride or 70% HF—30% pyridine solution at — 10 to + 20°C, 1-naphthol is the product formed in > 98% selectivity. In contrast, 2-naphthol is obtained in hydroxylation in super acid (HF—BF, HF—SbF, HF—TaF, FSO H—SbF ) solution at — 60 to — 78°C in > 98% selectivity (57). Of the three commercial methods of manufacture, the pressure hydrolysis of 1-naphthaleneamine with aqueous sulfuric acid at 180°C has been abandoned, at least in the United States. The caustic fusion of sodium 1-naphthalenesulfonate with 50 wt % aqueous sodium hydroxide at ca 290°C followed by the neutralization gives 1-naphthalenol in a ca 90% yield. 

Not all ionic liquids are the same, different combinations of anions and cations produce solvents with different polarities. No ionic liquids have shown themselves to be super-polar regardless of the method used to assess their polarities, ionic liquids come within the range of molecular solvents. Most general measures of overall polarity place ionic liquids in the range of the short- to medium-chain alcohols. 

To anhyd CuCl2 (30 mg, 0.223 mol) dissolved in anhyd DMF (2 mL) was added dioxouranium(VI) super-phthalocyanine (0.10 g, 0.11 mol), and the mixture was heated under N2 for 3 h at 120 C with stirring. After this time, the solvent was removed in vacuo and the resulting solid was washed with H20, acetone, and Et,0, and then vacuum dried to give a violet, microcrystalline powder yield 60 mg (95%). 

However, despite the detailed attention which has been given to many facets of carhonium ion chemistry, there has been, until recently, very little information available regarding their photoreactions. It is specifically through the use of the super acid solvents, e.g. HE—SbPs, FHSO3—SbFs, HE—BE3, etc., that a vast number of stable, long-lived carhonium ions have now become available for study. Many otherwise... 

The crystal of 2 OPr recrystallized from EtOH/H20 solution, and the mixed crystal of the same ethyl and propyl cinnamate derivatives (2 OEt and 2 OPr), on photoirradiation for 2h at room temperature with a 500 W super-high-pressure Hg lamp, afforded the highly strained tricyclic [2.2] paracyclophane (2 OEt-2 OPr-cyclo) crystal quantitatively (Maekawa et ai, 1991b). A crystal structure analysis was carried out of a single crystal of the complex of 2 OEt-2 OPr-cyclo with HFIP (recrystallization solvent) in a 1 2 molar ratio. Fig. 13 shows the molecular structure of 2 OEt-2 OPr-cyclo viewed along the phenylene planes. The short non-bonded distances and deformation of the benzene rings, as seen in Fig. 13, are common to those of [2.2] paracyclophanes, as previously reported (Hope et ai, 1972a,b). 

A recent development in liquid-liquid extraction has been the use of supercritical fluids as the extraction-solvent. Carbon dioxide at high pressure is the most commonly used fluid. It is used in processes for the decaffeination of coffee and tea. The solvent can be recovered from the extract solution as a gas, by reducing the pressure. Super critical extraction processes are discussed by Humphrey and Keller (1997). 

A packed absorption column removes an impurity from a gas stream by contact with a liquid solvent. The column is 3 ft in diameter and contains 25 ft of No. 2 plastic Super Intalox packing. The gas has an MW of 28, enters the column at 120°F, and leaves at 10 psig at a rate of 5000 scfm. The liquid has an SG of 1.15 and a viscosity of 0.8 cP. Determine ... 

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