Deuterated water

FIG. 27 Sum frequency generation spectra in ssp polarization of a deuterated water (D2O) film on mica as a function of the relative humidity (RH) at room temperature (296 K). Above 40% RH, the spectrum is very similar to that of ice. The free OD stretching mode can be seen above 91% RH. The bottom trace corresponds to the spectrum of the bulk waver/vapor interface. (From Ref. 72.)... 

Sutin et al have made a detailed study of the chloride-catalysed paths in deuterated water media, the exchange occurring more slowly in this solvent than in water. Accurate values of, in both water and heavy water, were obtained by spectrophotometry and enabled more precise rate parameters to be calculated. For aqueous media, values are 22.8 l.mole sec fork (n = 0.50 Af and 20 °C),... 

The occurrence of equilibrium (78) is confirmed by the incorporation of deuterium into molecular hydrogen from deuterated water. A brief study of the direct reaction between Ag and H2 indicates that both direct and catalysed reactions have the same velocity . ... 

D2O = deutered water. HPLC = high performance liquid chromatography. IS = internal standard. MeOH = methanol. MS = mass spectrometry. NMR = nuclear magnetic resonance. PDA = photodiode array detector. TEA = triethylamine. MTBE = methyl tert-butyl ether. 

Benedict, W. S., Gailar, N. Plyler, E. K. (1956). Rotation-vibration spectra of deuterated water vapour. Journal of Chemical Physics, 24, 1139-65. 

Figure 8.14 (a) Values of as a function of corresponding diffusion times (observation times) for each CdTe quantum dot. Four sets of measurements for one sample were conducted with diferent sized pinholes and different solvent as follows (1) 25 Xm pinhole, in water (2) 25 Xm pinhole, in deuterated water (3) 50 Xm pinhole. 

We have already mentioned that by simply adding deuterated water to the chloroform solution and shaking the NMR tube leads to H-D exchange, so that the OH signal disappears. 

Odutola, J. A., and T. R. Dyke. 1980. Partially deuterated water dimers Microwave spectra and structure. J. Chem. Phys. 72, 5062. 

Studies in deuterated water have shown that the hydroxyl proton does not end up in the ethanal formed. The decomposition of the 2-hydroxyethyl is not a simple P-elimination to palladium hydride and vinyl alcohol, which then isomerises to ethanal. Instead, the four protons stemming from ethene are all present in the initial ethanal product [6] (measured at 5 °C in order to suppress deuterium/hydrogen exchange in the product) and most authors have therefore accepted an intramolecular hydride shift as the key-step of the mechanism (see Figure 15.2). There remains some doubt as to how the hydride shift takes place. 

Mass spectra of ammonium nitrate and of a series of additional inorganic oxidizers were studied in both positive- and negative-ion mode by ESI-MS and ESI-MS/MS-CID [22, 23]. Characterization of ammonium nitrate by a series of typical cluster ions was confirmed by using isotojiicaUy labeled ammonium nitrate (ammonium- N, nitrate- N and nitrate- O) and deuterated water [22]. It was found that, at heated capiUary temperatures in the range... 

To initiate an H/D exchange reaction, a protein sample, initially in non-deuterated buffer, is incubated in a buffer with 50-90% mole fraction deuterated water. There are almost no restrictions on reaction conditions which allow exchange behavior to be studied as a function of protein and buffer composition, solution pH, and in the presence and absence of ligands. To follow the deuterium buildup of individual amide hydrogen or sets of hydrogens, several on exchange time points are sampled for each condition. 

The most commonly used organic solvent is deuterochloroform, CDCI3, which is an excellent solvent and is only weakly associated with most organic substrates. CDCI3 contains no protons and has a deuterium atom. For ionic compounds or hydrophilic compounds, the most common solvent is deuterated water, D2O. 

Labile protons can always be positively identified by in situ exchange with D2O. In practice, a normal H NMR spectmm is recorded then deuterium exchange of labile protons is achieved by simply adding a drop of deuterated water (D2O) to the NMR sample. Labile protons in -OH, -COOH, -NH2 and -SH groups exchange rapidly for deuterons in D2O and the H NMR is recorded again. Since deuterium is invisible in the iH NMR spectmm, labile protons disappear from the NMR spectmm and can be readily identified by comparison of the spectra before and after D2O is addition. 

It was found that only deuterated furanone was obtained if water had been replaced with deuterated water (D2O). This observation corroborated the fact that water was the hydrogen source in this reaction. Two possible mechanisms were proposed. The first one is described as follows (Scheme 18, path a) acetylene 119 can react with bimetallic species to afford /r, -acetylene complex 122, which reacts further with CO to give /tjTj -furanone... 

The enhancement of the fluorescent yield of terbium, europium, and gadolinium in heavy-water solutions was studied by Kropp and Windsor (105). They observed substantial increases in emission intensities for both terbium and europium compounds when ordinary water was replaced by deuterated water. No appreciable increase was observed for gadolinium, however. For terbium they also obtained the fluorescent lifetimes of the 5D4 state. 

The temperature dependences of the small-angle neutron scattering (SANS) from solutions and networks of poly(N,N -diethylacrylamide) or from copolymer of DEAAm and MNa (xMNa = 0.05) in deuterated water were measured [41]. Experimental dependences of the effective scattering cross-section... 

The protons of the hydroxy groups were deuterated by dissolving BP(OH)2 in cyclohexane and shaking the solution with deuterated water for several hours. After precipitation pump-probe measurements of BP(OD)2 in cyclohexane were recorded and are compared to BP(OH)2 in Fig. 4. Both samples were excited at 350 nm and probed at 505 nm. The delay of the emission rise of about 50 fs is equal in both cases and the coherent excitation of the vibrations is identical with respect to frequencies, phases and amplitudes. The ESIPT dynamics is obviously not altered by the deuteration and the mass of the proton has no influence on the transfer speed. This excludes that tunneling of the proton determines the speed of the transfer and the measurements provide the first proof for the passive behavior of the proton in the ESIPT. 

The matrix isolation procedure relies on the condensation of H20 and C02 on a liquid-nitrogen-cooled cold finger to form a stable matrix for radicals and other atmospheric species (Figure 9). Typically about 20 L of air are required to achieve the desired sensitivity for ambient measurements. A matrix of deuterated water (D20) narrowed the EPR line widths and improved the signal-to-noise ratio, and thus this matrix has been used for measurements since October 1982. Recent improvements in the use of this matrix isolation-EPR technique have been in the analysis of the spectra. 

Fig. 30. Zimm-plot and Kratky-plot of glycogen from edible mussels. Neutron small-angle measurements in deuterated water. The dotted line describes the scattering behavior of the ABC model with ac = aAp, and a branching probability of p = 0.2590,174)...

Interesting data about the effect of deuterated water molecules on electron transfer processes in reaction centres of PSl of plants have been ob-... 

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