Organic Hydroxy-compounds

Organic Hydroxy-compounds. Kell and McLaurin measured mass, p, and T of methanol in a nearly constant volume for temperatures between 150 and 300 °C, and pressures between 0.4 and 31 bar. They carefully analysed their results to see if use of second and fourth virial coefficients gave a better fit than use of second and third, as had been claimed earlier. They concluded that use of second and third virial coefficients was slightly to be preferred, and gave values of association constants for dimerization and trimerization. Tucker et al. gave values of association constants for various combinations of r-mers, based on their measurements of low-pressure compressibility at 15, 25, and 35 °C they found that a postulated mixture of monomers, trimers, and octamers fitted their data best. Kudchadker and Eubank, and Knoebel and Edmister measured the compressibility of methanol (in the ranges 25 to 200 °C, and 40 to 100 °C respectively) and presented values of the second virial coefficient only. 

Knoebel and Edmister studied the low-pressure compressibility of ethanol at 60, 80, and 100 °C, and reported values of B,. Coimsell et al. determined the molar volume of ethanol at the saturation vapour pressure, 

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The chemistry of silicon oxygen compounds with SiOs and SiC>6 skeletons in aqueous solution is of special interest. It has been speculated that such Si(IV) complexes with ligands derived from organic hydroxy compounds (such as pyrocatechol derivatives, hydroxycarboxylic acids, and carbohydrates) may play a significant role in silicon biochemistry by controlling the transport of silicon. 

The precipitation of aluminium hydroxide by solutions of sodium hydroxide and ammonia does not take place in the presence of tartaric acid, citric acid, sulphosalicylic acid, malic acid, sugars, and other organic hydroxy compounds, because of the formation of soluble complex salts. These organic substances must therefore be decomposed by gentle ignition or by evaporating with concentrated sulphuric or nitric acid before aluminium can be precipitated in the ordinary course of qualitative analysis. 

As already noted, the structures of hydroxy-acids, which include B(0H)3 and Te(OH)g, are described in Chapter 14 with hydroxides, to which they are more closely related stmcturally, the molecules being linked by long 0-H—0 bonds (two from each OH) as in many organic hydroxy-compounds. One form of metaboric acid, consisting of cyclic 6303(011)3 molecules, is also of this type, for the three 0 atoms in the ring are not involved in hydrogen bonding. 

Diagram generated from data compiled by Gmehling, J., Onken, U., and Arlt, W. 1982. Vapor-Liquid Equilibrium Data Collection - Organic Hydroxy Compounds Alcohols, Dechema, Frankfurt, Germany, vol. 1, p. 165.)... 

J. Gmehling and U. Onken, Vapor-Liquid Equilibrium Data Collection, Organic Hydroxy Compounds Alcohols, DECHEMA Germany, 1977. 

An organic isocyanate (MDI or a pre-polymer) with a hydroxy compound. The isocyanates are potent respiratory sensitizers, the risk increasing with volatility... 

One of the most useful ways of introducing fluorine into organic compounds is the placement of the hydroxyl group in alcohols hydroxy compounds, and carboxylic acids Methyl alcohol reacts with anhydrous hydrogen fluoride at 100 500 °C in the presence of aluminum fluoride [60, 61], zinc fluoride [62] chromium fluonde [63], or a mixture of aluminum and chromium fluondes [64] to give a 20-78% yield of fluoromethane Attempted fluorinations of higher alcohols by this method failed [60]... 

Methyl-4-hydroxyquinazoline reacts with organic halides, in the presence of sodium methoxide, to give 3-substituted 2-methyl-4(3i/)-quinazolinones. The 0-acetyl derivative of 4-hydroxyquinazoline has been prepared under anhydrous conditions and gives the hydroxy compound with water or with lithium aluminum hydride. The N-3 acetyl derivative, however, is more stable and gives 3-methyl-4(31/)-quinazolinone with lithium aluminum hydride. ... 

K Shirahama, M Hayashi, R Matuura. The effects of organic additives on the solubilities and CMC s of potassium alkyl sulfates in water. I. The effects of several hydroxy compounds. Chem Bull Jpn 42 1206-1212, 1969. 

Nitrosyl perchlorate Organic materials Perchloric acid Alcohols Permanganic acid Organic materials Peroxodisulfuric acid Organic liquids Potassium dioxide Ethanol Potassium perchlorate Ethanol Potassium permanganate Ethanol, etc. Ruthenium(VIII) oxide Organic materials Silver perchlorate Aromatic compounds Sodium peroxide Hydroxy compounds Uranium hexafluoride Aromatic hydrocarbons, etc. Uranyl perchlorate Ethanol See v-halomides Alcohols... 

One of the most systematic investigations into the use of organic chemical microscopy was made by Dunbar and his associates, who used a series of specific reagents to develop specific tests for various functional groups. Methods were developed for amines [24,25], carboxylic acids, anhydrides, and acid chlorides [26,27], aldehydes and ketones [28], hydroxy compounds [29], amino acids [30], and cations [31]. 

Activated esters of A-alkoxycarbonylamino acids are prepared by two approaches, activation of the acid followed by reaction with the hydroxy compound, and trans-esterification. Most of the products are stable enough to be purified by washing a solution of the ester in an organic solvent with aqueous solutions. A few that are not crystalline are purified by passage through a column of silica. The commonly used method for their preparation is addition of dicyclohexylcarbodiimide to a cold mixture of the reactants in dimethylformamide or ethyl acetate. The first Boc-amino acid nitrophenyl esters were obtained using pyridine as solvent. Pyridine generates the nitrophenoxide ion that is more reactive. For one type of ester, 2-hydroxypyridino... 

In the fourth and final chapter, Howard Haubenstock discusses asymmetric reduction of organic molecules. Within this general topic of wide and continuing interest, Haubenstock s chapter deals with chiral derivatives of lithium aluminum hydride, their preparation from suitable amino or hydroxy compounds, and their use in reducing carbonyl groups. Related reactions of the Meerwein-Ponndorf-Verley type or involving tri-alkylaluminum reagents are also presented. 

Many enzymes are known which will transfer glycosyl functions specifically to receptor hydroxy compounds, but although this possibility offers means for obtaining specific glycosides it has not been used extensively, largely because the techniques are unfamiliar to the organic chemist and because they are not well suited to the preparation of large amoimts of materials. Pridham has surveyed the enzymic reactions... 

F. S. Brown and C. R. Bury 6 obtained colloidal solutions of phosphorus pentoxide in nitrobenzene by stirring the mixture in the presence of alcohols or organic acids. The hydroxy-compound is absorbed and peptizes the pentoxide. Traces of moisture cause coagulation. Cone. soln. set to gels on keeping. 

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