Deuterated compounds Water

Shono et al. (1979) describe a method for hydro-de-diazoniations which is simple, gives excellent yields, and is claimed to show no unfavorable substituent effects (14 examples). It consists of the addition of thiophenol (7 equiv.) to a suspension of an arenediazonium tetrafluoroborate in a mixture of water and pentane (10 1) at room temperature. After the completion of N2 evolution, excess thiophenol is removed by addition of Na2C03. The usual work-up gave the corresponding hydrocarbon in 84-100% yield and diphenylsulfide. The deuterated compounds are obtained if one uses C6H5SD and D20. 

Cooper and coworkers30 measured also the absorption spectrum of transient species produced in the radiolysis of pure liquid DMSO-d6 and found the same absorption of the first two bands, however, the intensity of the absorption is about 30% larger in the case of the deuterated compound for both of the absorption bands. The intensity of the absorption is given by Ge, but as the same change was found for both bands it seems most reasonable that the 30% difference arises from a change in G rather than in e. This is similar to water, where the fraction of ions which become free ions is substantially larger for the deuterated compound32. 

Thierrin J, GB Davis, C Barber (1995) A ground-water tracer test with deuterated compounds for monitoring in situ biodegradation and retardation of aromatic hydrocarbons. Ground Water 33 469-475. 

The determination of alkyltrimethyl ammonium compounds with the general formula RN (CH3)3X surfactant were performed using CF-FAB and ESI. The compounds examined were dodecyl-, tetradecyl-, and hexadecyl-trimethyl ammonium compounds dissolved in water. The product ion spectra of dodecyltrimethyl ammonium compound and its methyl-deuterated homologue were presented. The product ion at m/z 60 [(CH3)3NH]+of the non-deuterated compound at m/z 228 was the only ion that shifted after deuteration to m/z 69 [38],... 

As a consequence, benzylic protons in a- and y-alkyl groups (but not in p-positions) are acidic and in water are in equilibrium with the corresponding methylenepyrans water at pH <5. Because the symmetric y-methylenepyrans (y-anhydrobases) are more stable than a-methylenepyrans [57], the isotopic exchange with deuterium oxide proceeds about ten times faster in y than in a, and this allows the synthesis of regiospecifically deuterated alkylpyrylium salts, which can then be converted into other deuterated compounds because the reaction with nucleophiles takes place even faster [58, 59],... 

However, the temperature-control method is used for the preparation of the deuterated compounds. Although the other method is safer, there are two reasons which justify using the temperature-control method in this case. First, special care must be taken to maintain isotopic purity in the preparation of the deuterated compounds. Hence the reactants must be free of water, and this is better accomplished if the solvent is dried and handled in the vacuum line, where it cannot come into contact wdth atmospheric water. Second, because the reaction is run on a small scale, the consequences would be minimal if it were to get out of control. 

Weigl studied the exchange reaction between ascorbic acid and heavy water. An examination of the 0—H and C—H stretching frequency region of the normal and the deuterated compound led him to the conclusion that ascorbic acid contains labile hydrogen atoms attached to both carbon and oxygen. 

Many fully or partially deuterated compounds are available commercially, and the extent of deuterium labelling (see Section 2.9) can be determined by mass spectrometry, density measurements (after conversion into water) or IR spectroscopy. 

Organomagnesium and organolithium compounds are such strong bases that they will react immediately with any acid that is present in the reaction mixture—even with very weak acids such as water and alcohols. When this happens, the organometallic compound is converted into an alkane. If D2O is used instead of H2O, a deuterated compound will be obtained. 

The couple in the presence of water reduces halides in ethereal solvents in moderate to high )delds at room temperatures. It has been used primarily to provide deuterated compounds. 

Molecular water is characterized by a deformation mode around 1630 cm This band cannot always be discerned because many other surface species (carbonates, nitrates) manifest bands in this region. The band should be shifted to about 1200 cm when using deuterated compounds. Moreover, when the H/D exchange is only partial, the deformation of the HOD molecule should be observed around 1415 cm (495). 

Most elements have NMR-active nuclei, i.e., nuclei possessing a magnetic moment. For surfactant systems, the situation is very good in that H and C nuclei, which occur in most surfactant molecules, have good NMR properties. For relaxation work, however, it is often advantageous to use NMR on selectively deuterated compounds. F NMR is very useful for the study of fluorocarbon surfactants, P NMR for phospholipids, and Si NMR for silicon surfactants. For studies of water molecules we have a choice between three good alternatives H, H, and NMR. Many common counterions, e.g., Na, Li, Rb, Cs, F, Cl, Br, and I, have highly sensitive nuclei, whereas others, such as K" ", Mg " ", Ca ", and SO ", have lower sensitivity and are more difficult to study. 

Deuterated compounds (CgDg and CDCI3) used to prevent contribution of the H signals of the second liquid phase are not practically mixed with water and they exist in pores as a separated liquid phase, which is in contact with the water phase. The trends in AG(C ) show the vertical sections for PSl samples in all media (Fignre 3.12). Their appearance is linked to the fact that water is unfrozen... 

Thierrin, J., G. B. Davis, and C. Barber. 1995. A Ground-water Tracer Test with Deuterated Compounds for Monitoring In Situ Biodegradation and Retardation of Aromatic Hydrocarbons, Ground Water, vol. 33, no. 3, pp. 469-475. 

During the course of these mechanistic studies a wide range of possible applications of this reaction have been revealed. When the reduction is carried out with lithium aluminum deuteride and the anion complex decomposed with water, a monodeuterio compound (95) is obtained in which 70% of the deuterium is in the 3a-position. Reduction with lithium aluminum hydride followed by hydrolysis with deuterium oxide yields mainly (70 %) the 3j5-di-epimer (96), while for the preparation of dideuterio compounds (94) both steps have to be carried out with deuterated reagents. ... 

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