Acetic acid, Dichloro

Figure 7. Graph of D° vs. molecular weight for PBLG in dichloro-acetic acid. PBLG is in a random-coil conformation.

Recently, studies of the conformation of oligomers were extended to peptides derived from /3-methyl-L-aspartates. Their synthesis (n = 2 up to 14) was described by Goodman and Boardman (82), and later the specific rotations of their solutions in dimethyl formamide, dichloro-acetic acid and in chloroform were determined (83). The oligomers exist in a random-coil form in the first two solvents, but helices become stable in chloroform for n — 11 and 14. These peptides are unusual since their L-amino-acid residues produce a left-hand helix (84, 85) whereas most of the investigated polyamino acids crystallise as a right-hand helix (86). 

The alcoholysis reaction was found to be first order in both the silane and the catalysts, and of intermediate order in the alcohol, when catalyzed by carboxylic acids. When catalyzed by dichloro-acetic acid, the reaction has a Hammet p value of +0.43. This is consistent with a concerted displacement reaction between the alkoxysilane and the complex involving the alcohol and the carboxylate anion. The intermediate is a negatively charged intermediate, probably a penta-substituted silicon species. 

Hydroxy quinoline is obtained by the reaction between o.phenylene diamine and dichloro acetic acid... 

The solubility of the electrically conductive form, the protonated EM salt, is poor in common solvents, and so, initially, EM base was used to form films from NMP solution before conversion to the salt with HC1. Attempts to increase solubility by incorporating pendent alkyl chains were counterproductive as such polymers had significantly lower electrical conductivity. Better solubility is obtained for salts produced with sulphonic acids. Thus the camphor sulphonic acid salt dissolves in m-cresol and the 2-acrylamido-2-methyl-l-propanesulphonic acid salt dissolves in dichloro-acetic acid. The use of these systems, and polymer synthesised below room temperature, has facilitated the spinning of fibres with oriented polymer chains and conductivity along the fibre as high as 2x 105f2-Im-1 (Pomfret et ai, 1998). 

DMT protecting group on the 5 -OH of the growing chain is removed by the addition of dichloro-acetic acid, which leaves other protecting groups intact. The DNA chain is now elongated by one unit and ready for another cycle of addition. Each cycle takes only about 10 minutes and elongates more than 98% of the chains. 

ETHANE PENTACHLORIDE (76-01-7) Incompatible with water, producing dichloro-acetic acid. May self-ignite in air. Contact with aluminum, cadmium, mercury, hot iron, alkalis, alkali metals forms chloroacetylene gas, which is spontaneously explosive in air. Contact with potassium may explode or form shock- and friction-sensitive materials. Incompatible with potassium-sodium alloy. 

EC (ethyl cellulose)/glacial acetic acid + dichloro acetic acid [53]... 

C,HC1,0,]- HOOCCClj Reaction of HO- with dichloro-acetic acid (Ti H202)/ H2O, acid pH EPR/ 300 2.00832 Cl 0.31 68Moel/ 69Becl, 64Dixl... 

Two parallel paths have been identified in the reduction of monochloro- and dichloro-acetic acids by uranium(iii). The reactions have been studied in various binary alcohol-water mixtures as well as in aqueous media. Under the latter conditions the rate may be described by... 

Fig. 6.8. Intrinsic viscosity [q] as a function of the molar mass for poly(glutamic acid benzyl ester) (PGE) in two different solvents at 25 X (data from [62]).The slope of 1.7 for the [q]-M-re a-tionship for chloroform as a solvent indicates a rod-like (helical) structure, whereas in dichloro-acetic acid a slope of 0.87 indicates a flexible coil for the solution structure...

A Simple Gas Chromatographic Method for the Measurement of Dichloro-acetic Acid in Plasma or Urine... 

C5H8CI2O2 dichloro-acetic acid propyl ester 37587-81-8 ... 

Similar reactions of the protic acids with benzanthrone and dibenzanthrone were carried out in all cases titrations with acetic, monochloro and dichloro-acetic acids were unsuccessful indicating relatively weak interactions of the acids with the ketones. 

Finally we must know how ordered or disordered the polymer is. If the forces between residues are not strong compared to the solvent-residue interactions, or if different helical conformations have nearly the same stability, then there may be different conformations present in solution. We usually expect a polymer to become more ordered as the temperature is decreased, but this is not necessarily true. If solvent—residue attractions dominate at low temperature, a polymer may change from an ordered helix at high temperature to a disordered coil at low temperature. Poly-y-benzylglutamate in ethylene dichloride-dichloro-acetic acid shows this behavior [1]. 

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