Soluble in solvent

When viscometric measurements of ECH homopolymer fractions were obtained in benzene, the nonperturbed dimensions and the steric hindrance parameter were calculated (24). Erom experimental data collected on polymer solubiUty in 39 solvents and intrinsic viscosity measurements in 19 solvents, Hansen (30) model parameters, 5 and 5 could be deterrnined (24). The notation 5 symbolizes the dispersion forces or nonpolar interactions 5 a representation of the sum of 8 (polar interactions) and 8 (hydrogen bonding interactions). The homopolymer is soluble in solvents that have solubility parameters 6 > 7.9, 6 > 5.5, and 0.2 < <5.0 (31). SolubiUty was also determined using a method (32) in which 8 represents the solubiUty parameter... 

The impurities present in aromatic nitro compounds depend on the aromatic portion of the molecule. Thus, benzene, phenols or anilines are probable impurities in nitrobenzene, nitrophenols and nitroanilines, respectively. Purification should be carried out accordingly. Isomeric compounds are likely to remain as impurities after the preliminary purifications to remove basic and acidic contaminants. For example, o-nitrophenol may be found in samples ofp-nitrophenol. Usually, the ri-nitro compounds are more steam volatile than the p-nitro isomers, and can be separated in this way. Polynitro impurities in mononitro compounds can be readily removed because of their relatively lower solubilities in solvents. With acidic or basic nitro compounds which cannot be separated in the above manner, advantage may be taken of their differences in pK values (see Chapter 1). The compounds can thus be purified by preliminary extractions with several sets of aqueous buffers... 

The polymer, being amorphous, is soluble in solvents of similar solubility parameter, grades with low residual acetate being dissolved in solvents of solubility parameter between 19.8 and 22 MPa. ... 

Nitration of cellulose followed by plasticisation of the product with camphor has the effect of reducing the orderly close packing of the cellulose molecules. Hence whereas cellulose is insoluble in solvents, except in certain cases where there is chemical reaction, celluloid is soluble in solvents such as acetone and amyl acetate. In addition the camphor present may be dissolved out by chloroform and similar solvents which do not dissolve the cellulose nitrate. 

Only a limited number of coal-denved pitches were examined by H NMR because of their low solubility in solvents commonly used m conventional proton magnetic resonance. Table 12 reports the distribution of hydrogen for three of the pitches. Unlike coal-tar pitches, which typically have over 85% of the hydrogen bonded to aromatic carbon, the matenals listed in Table 12 are characterized by a high content of aliphatic hydrogen. 

Vulcanization changes the physical properties of rubbers. It increases viscosity, hardness, modulus, tensile strength, abrasion resistance, and decreases elongation at break, compression set and solubility in solvents. All those changes, except tensile strength, are proportional to the degree of cross-linking (number of crosslinks) in the rubber network. On the other hand, rubbers differ in their ease of vulcanization. Since cross-links form next to carbon-carbon double bonds. 

There have been very few examples of PTV derivatives substituted at the vinylene position. One example poly(2,5-thienylene-1,2-dimethoxy-ethenylene) 102 has been documented by Geise and co-workers and its synthesis is outlined in Scheme 1-32 [133]. Thiophene-2,5-dicarboxaldehyde 99 is polymerized using a benzoin condensation the polyacyloin precursor 100 was treated with base to obtain polydianion 101. Subsequent treatment with dimethyl sulfate affords 102, which is soluble in solvents such as chloroform, methanol, and DMF. The molar mass of the polymer obtained is rather low (M = 1010) and its band gap ( ,.=2.13 eV) is substantially blue-shifted relative to PTV itself. Despite the low effective conjugation, the material is reasonably conductive when doped with l2 (cr=0.4 S cm 1). 

The McMuny coupling route has been utilised by Iwalsuki and co-workers the synthesis of PDBoxTV 85 (Scheme 1-29) [129]. Dialdehyde 90 is polynn ized in the presence of titanium tetrachloride and zinc dust. Molecular weights 35000 are reported and the polymer is freely soluble in solvents such as chloi form. The reported absorption maximum (605 nm) was close to that observed I the Blohm route [I27J. 

Amorphous bisphenol-A polyarylates are soluble in dioxane and in chlorinated solvents such as CH2C12, 1,2-dichlororethane, 1,1,2-trichloroethane, and 1,1,2,2-tetrachloroethane while semicrystalline and liquid crystalline wholly aromatic polyesters are only sparingly soluble in solvents such as tetrachloroethane-phenol mixtures or pentafluorophenol, which is often used for inherent viscosity determinations. 

A methyl group can be placed on cobalt in dicyano[cobyrinic acid heptamethyl ester] when it is treated with excess methyl magnesium iodide (the ester side chains being converted into tertiary alcohol groups). The alkylation could also be achieved using lithium alkyls (176). Presumably this reaction would be successful with any corrinoid which is soluble in solvents compatible with Grignard reagents. 

Among the physical characteristics of these nonlinear condensation polymerizations, the occurrence of a sharp gel point is of foremost significance. At the gel point, which occurs at a well-defined stage in the course of the polymerization, the condensate transforms suddenly from a viscous liquid to an elastic gel. Prior to the gel point, all of the polymer is soluble in suitable solvents, and it is fusible also. Beyond the gel point, it is no longer fusible to a liquid nor is it entirely soluble in solvents. Linear polymers, on the other hand, remain soluble in suitable solvents and fusible to liquids as well (unless the melting point is above the temperature of thermal decomposition), regardless of the extent of condensation. 

Modification of carboxylate groups with diamines also may be done in organic solvent for those molecules insoluble in aqueous buffers. Some peptides are quite soluble in solvents such as DMF and DMSO, but relatively insoluble in water. Such molecules may be reacted in these... 

Hydrogen has a low solubility in solvents for example, at ambient conditions, only 0.018 and 0.078 mL of gaseous H2 dissolves into each milliliter of water and ethanol, respectively. However, the solubility is much more pronounced in metals. Palladium is particularly notable in this respect, which dissolves about 1000 times its volume of the gas. The adsorption of hydrogen in steel may cause "hydrogen embrittlement," which sometimes leads to the failure of chemical processing equipment [4],... 

In solvents that have donor properties, solubility leads to complex formation to give species such as S A1C13 (where S is a solvent molecule). Beryllium chloride is soluble in solvents such as alcohols, ether, and pyridine, but slightly soluble in benzene. 

For the heavier alkaline earth elements the characterized compounds are octahedral monomers, dimers, or separated-ion species. The complexes M(SR)2 (M=Ca, Sr, Ba) have been obtained by aminolysis and proved to be soluble in solvents such as py these compounds decompose rather cleanly to their metal sulfides.86 The monomeric species include [M(EMes )2(thf)4] (M=Ca, Sr, Ba E=S, Se),87 89 [Ca(SC6F5)2(py)4],90 [Ca(SMes )2(18-crown-6)] thf,90 or [Ba(Se-Trip)2(18-crown-6)].87 Only a dimeric barium derivative, [Ba(SeTrip) (py)3(thf)]2, has been described.87 For these elements separated ion-triple species, such as [M(18-crown-6)(hmpa)2][EMes ]2 (M=Ca, Sr, Ba E=S, Se)87,88,91 or contact/separated ion-triple species as [Ba(SMes )(18-crown-6)(hmpa)][SMes ] have been reported.91... 

Adequate precaution and care must be exercised in determining partition coefficients based on the solubility data as S, is not the solubility of substance A in pure Solvent a , but rather the solubility in Solvent a saturated with Solvent cb ... 

An ideal polarity probe based on photoinduced charge transfer and solvent relaxation should (i) undergo a large change in dipole moment upon excitation but without change in direction, (ii) bear no permanent charge in order to avoid contributions from ionic interactions, (iii) be soluble in solvents of various polarity, from the apolar solvents to the most polar ones. 

Although Reichardt s dye itself is not soluble in solvents of very low polarity (diphenyl ether is the lower limit), a related dye functionalized with /-butyl groups which has increased solubility in hydrocarbons, shown in Figure 1.15, has been used to extend the scale. However, attempts to use a similar approach to gain... 

If an analyte is definitely insoluble or only soluble in solvents that are not acceptable for the standard MALDI sample preparation technique, it can alternatively be ground together with the solid matrix, preferably in a vibrating ball mill. The resulting fine powder is then spread onto the target. To avoid contamination, nonadherent material should be gently blown away from the target before insertion into the ion source. [103,108,109]... 

Soluble in solvents (U.S. EPA, 1985), including ethanol and ether (Weast, 1986)... 

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