Saturated Deuterium Oxide

Deuteration of the accessible hydroxyl groups is accomplished with saturated deuterium oxide vapor at room temperature. The extent of deuteration and therefore accessibility can be estimated gravimetrically by infrared spectroscopy. Accessibility rather than crystallinity is measured because deuteration of the hydroxyl groups on crystallite surfaces can also occur. 

Sowden and Schafferi also examined the reaction of D-glucose in saturated deuterium oxide-calcium hydroxide-dz at 25°. All three of the principal components of these reaction mixtures, D-glucose, D-mannose, and D-fructose, were isolated in these experiments and their content of deute-... 

To study boric complexes of carbohydrates in solution the saccharides are dissolved in saturated deuterium oxide solutions of borax and then subjected to NMR spectroscopy (50). The proton spectra of glucose and xylose in presence and absence of borax are shown in Fig. 9. 

Deuteration. When cellulose is treated with saturated deuterium oxide vapor at roan ten rature, the easily accessible hydroxyl groi exchange re idly, and a less accessible coi xxient exchanges more slowly. Other hydroxyl groups do not exchange. The easily accessible hydroxyl groiq>s have been equated with the amorphous... 

A solution of 3j5-hydroxy-5a-androstan-7-one (10, 50 mg) in methanol-OD (4 ml) is saturated with deuterium oxide containing 5 % sodium deuterioxide (prepared by reacting sodium with deuterium oxide) and heated under reflux for 3 days. (If the heated solution becomes turbid due to supersaturation, a few drops of methanol-OD should be added until a clear solution is obtained. The use of a drying-tube on top of the condenser is advisable to avoid isotope dilution from moisture.)... 

The estimation of flow functions from an actual experiment is reported next. A multi-rate primary drainage experiment was conducted on a Texas Cream limestone sample. Hexadecane was used as the oleic phase and deuterium oxide (D20) was used as the aqueous phase. Protons are imaged, so only the oil phase is observed. The pressure drop data, production data and saturation data are shown in Figures 4.1.11-... 

An operational approach to the determination of the acidity of solutions in deuterium oxide (heavy water) was suggested by Glasoe and Long. This quantity, pD, is determined in a cell consisting of an aqueous (H20) glass electrode and a saturated aqueous calomel reference electrode on the basis of the equation... 

The double bond of 9-allylcarbazoles can be moved into conjugation with the nitrogen by treatment with potassium rcrt-butoxide in dimethyl sulfoxide the cis-prop-l-enyl isomers were formed initially in studies with 9-allyl-carbazole, 9-allyl-3-chlorocarbazole, 9-allyl-3-nitrocarbazole, and 9-allyl-3,6-dichlorocarbazole. " Such isomerizations must proceed via a car-banion produced by proton abstraction from the saturated carbon on nitrogen. Indeed, when the red anion from 9-benzylcarbazole, formed using n-butyllithium, was quenched with deuterium oxide, the 9-CHDPh derivative was obtained. When the anions from 9-ally 1-carbazoles in the series 81... 

At 25°C, paj, values on the molality scale are 0.043 unit higher than on the molarity scale,since the density of deuterium oxide is higher than that of water. The accuracy of measured pD values depends in part on the variability of the liquid-junction potential between the deuterium oxide and saturated potassium chloride in the reference electrode. 

Later, Goto published data for the behavior of n-glucose at 25° in saturated, calcium hydroxide solutions (enriched with deuterium oxide) which, he claimed, confirmed Fredenhagen and Bonhoeffer s observations. Goto pointed out, however, that the mechanism involving the dimeric intermediate lacked kinetic proof and permitted no known role for the catalyst. 

Topper and Stetten s work involved (1) the reaction of n-glucose-l-d in ordinary water saturated with calcium hydroxide, and (2) the reaction of D-glucose in deuterium oxide saturated with calcium hydroxide-d2. These isomerizations were carried out at both 25° and 35°. In the experiments with D-glucose-l-d at 35°, the n-mannose isolated (as the phenylhydrazone) contained 44 % of the deuterium in the starting substance, all of which was retained at Cl, whereas the n-fructose isolated (as the phenylosazone) retained 94% of the deuterium. A similar result (100% retention of deuterium) was reported for the n-fructose isolated from the reaction at 25°. These figures for n-fructose were based on the assumption that 50 % of the... 

Fig. 9a and b. NMR spectra of deuterium oxide solutions (dotted line) and deuterium oxide solutions saturated with borax (solid line) a) glucose b) xylose (50). 

Four nucleophilic aromatic substitution reactions with amines have been studied for deuterium isotope effects. Hawthorne (81) found that the rates of reaction of o- and p- nitrochlorobenzene with piperidine in xylene are not altered by substitution of deuterium for hydrogen on the amino group of the nucleophile. Similarly, 2,4-dinitrochlorobenzene reacts at identical rates with -butylamine and with iV,iV-dideuterio-n-butylamine containing 0.75% ethanol (76). Under the conditions of the rate measurements the deuterated amine does not undergo exchange with either the chloroform or the ethanol present. Finally, the reaction of trichloro-s-triazene with aniline shows no isotope effect with AT,JV-dideuterioaniline in benzene as well as in benzene saturated with deuterium oxide (82). 

The generality of this approach, including the reliability of the NMR data obtained in acetonitrile-c/3/deuterium oxide/formic acid mixtures instead of deuteriochloroform, was demonstrated by its successful application to the secondary alcohols of known absolute configuration (205.1—205.18, shown in Figure 205, including saturated, unsaturated, aromatic, acyclic, and cyclic compounds). 

While keeping the collected deuterioammonia at dry ice-isopropyl alcohol temperature, lithium wire (10 mg) is added, followed by a solution of 3/3-hydroxy-5a-cholest-7-en-6-one (161 50 mg) in anhydrous tetrahydrofuran (4 ml). The reaction mixture is stirred for 20 min, the cooling bath is then removed and the ammonia is allowed to boil under reflux for 40 min. A saturated solution of ammonium chloride in tetrahydrofuran is added dropwise until the deep blue color disappears and then the ammonia is allowed to evaporate. The residue is extracted with ether and the organic layer washed with dilute hydrochloric acid and sodium bicarbonate solution and then with water. Drying and evaporation of the solvent gives a semicrystalline residue which is dissolved in acetone and oxidized with 8 N chromic acid solution. After the usual workup the residue is dissolved in methanol containing sodium hydroxide (0.2 g) and heated under reflux for 1 hr to remove any deuterium introduced at C-5 or C-7. (For workup, see section II-B). 

Smith and Burwell [61) showed that the reaction of deuterium with j9.io-octalin, which is catalyzed by reduced platinum oxide, yields a mixture of cis- and /mws-decalins containing an average of nearly three deuterium atoms per molecule. Under the same conditions J -octalin gave somewhat less of the cis isomer but the saturated products contained an average of two deuterium atoms per molecule. From a detailed analysis of the distribution of deuterium in the products they concluded that most of the cis- and all of the frans-decalin produced from... 

Ru" (0)(N40)]"+ oxidizes a variety of organic substrates such as alcohols, alkenes, THE, and saturated hydrocarbons. " In all cases [Ru (0)(N40)] " is reduced to [Ru (N40)(0H2)] ". The C— H deuterium isotope effects for the oxidation of cyclohexane, tetrahydrofuran, 2-propanol, and benzyl alcohol are 5.3, 6.0, 5.3, and 5.9 respectively, indicating the importance of C— H cleavage in the transitions state. For the oxidation of alcohols, a linear correlation is observed between log(rate constant) and the ionization potential of the alcohols. [Ru (0)(N40)] is also able to function as an electrocatalyst for the oxidation of alcohols. Using rotating disk voltammetry, the rate constant for the oxidation of benzyl alcohol by [Ru (0)(N40)] is found to be The Ru electrocatalyst remains active when immobilized inside Nafion films. 

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