Deuterium Oxide D2O

Table 21.1 compares some of the common properties of H2O with those of D2O. Deuterium oxide, or heavy water as it is commonly called, is used in some nuclear reactors as a coolant and a moderator of nuclear reactions (see Chapter 23). D2O can be... 

Two other isotopes are known fH, whose nucleus contains a proton and a neutron, and fH, whose nucleus contains a proton and two neutrons. The fH isotope, deuterium, makes up 0.0156% of naturally occurring hydrogen. It is not radioactive and is often given the symbol D in chemical formulas, as in D2O (deuterium oxide), which is known as heavy water. 

MIC failures could have ecological impacts as well such as loss of tritiated D2O (Deuterium Oxide or Heavy Water) to the environment [22]. Sulphate-reducing bacteria have been responsible for massive fish kills, killing of sewer workers by development of poisonous dawn fogs , and killing of rice crops in paddies via oxygen depleting [14]. 

Deuterium oxide (D2O) is water in which the protons ( H) have been replaced by their heav ler isotope deuterium ( H) It is readily available and is used in a vanety of mechanistic studies in organic chemistry and biochemistry When D2O is added to an alcohol (ROH) deuterium replaces the proton of the hydroxyl group... 

Substitution of deuterium for hydrogen at the a carbon atom of an aldehyde or a ketone is a convenient way to introduce an isotopic label into a molecule and is readily carried out by treating the carbonyl compound with deuterium oxide (D2O) and base... 

Deuterium oxide [7789-20-0] M 20, f 3.8°/760mm, b 101.4°/760mm, d 1.105. Distd from alkaline KMnOa [de Giovanni and Zamenhof Biochem 7 92 79 I963. NOTE that D2O invariably contains tritiated water and will therefore be RADIOACTIVE always check the radioactivity of D2O in a scintillation counter before using. 

Repeat the analysis with deuterium oxide (D2O). Are the vibrational frequencies the same, larger or smaller than those in water Rationalize your observations. Are the changes in vibrational frequencies greatest for bond stretching or angle bending motions ... 

Deuterio-3-iiitro-l,6-iiaphthyridiiie (168) was prepared from 4-chloro-3-iiitro-l,6-iiaphthyridiiie (166) by a reaction with tosyl hydrazide and subsequent hydrolysis of the 4-tosylhydrazino derivative (167) with Na2C03/ D2O solution (83RTC359). 7-Deuterio-l,8-naphthyridin-2(lH)-one was prepared by heating l,8-naphthyridin-2(lH)-one with deuterium oxide at 230°C for 35 h (85JHC761). Tliis deuterio compound could be converted into 2-chloro-(or 2-ethoxy-) 7-deuterio-3,6-dinitro-l,8-naphthyridine. 

There is a limited amount of information on the extent of hydration of aldehydes in deuterium oxide. Gruen and McTigue (1963a) concluded that for five aliphatic aldehydes at 25° C is 16 % to 26 % smaller in D2O... 

The only kinetic isotope effects so far reported for these reactions are those given by Pocker (1960), without experimental detail. He reports closely similar values for the rates of solvent-catalysed hydration of the species CHg. CHO, CD3. CHO, CH3. CDO and CD3. CDO in water at 0° C the replacement of CH3 by OD3 increases the velocity by about 7%. The same effect is reported for solutions in deuterium oxide at 0° C, presumably super-cooled. A comparison was also made of rates of hydration in HjO and DgO at 0°C, giving the following values for k(H.z0)lk(T>20) in presence of different catalysts H+/D+, 1 -3 AcOH/AcOD, 2 5 AcO , 2-3 H2O/D2O, 3-6. Almost exactly the same ratios were obtained by measuring rates of dehydration at 25° C in dioxan containing 10% of H2O or D2O and various catalysts. The presence of a considerable solvent isotope effect is consistent with the mechanism given in Section IV,B, and it would not be expected that substitution of deuterium on carbon would have an appreciable effect on the rate. 

It was detected by Urey, Brickwedde and Murphy in 1932. It occurs in all natural compounds of hydrogen including water, as well as in free hydrogen molecules at the ratio of about one part per 6,000 parts hydrogen. The principal application of deuterium is in tracer studies for measuring rates and kinetics of chemical reactions. It also is used in thermonuclear reactions and as a projectile in cyclotrons for bombardment of atomic nuclei to synthesize isotopes of several transuranium elements. Deuterium oxide, D2O, or heavy water is used as a neutron moderator in nuclear reactors. 

Comparison with Experiment. DEUTERIUM OXIDE AND WATER MIXTURES. For a solute showing no preferential solvation (K = 1, AGps0, = 0), then dp = xp from Equation 65, and a plot of 5 against xp is a straight line. Such behavior has been found for the fluoride ion in D2O-H2O mixtures (24). The free energy of transfer from Equation 67 for an ion which shows no preferential solvation will be given by... 

For each of the alkali metals used the e.s.r. spectrum at 77°K consisted of a single narrow line (Fig. 12a, b). The relevant features of the e.s.r. spectra are summarized in Table 4. The absence of any effect of the cation on the line width or p-factors shows conclusively that the electron has been transferred completely from the alkali metal atom and is therefore not held in an expanded orbital around the cation, as suggested by Jortner and Sharf (1962). The difference in line width between the spectra in D2O (3-2 G) and in water (9-2 G) suggests that there is a hyperline interaction between the electron and the protons in water. This was shown conclusively by the observation of seven equally spaced hyperfine lines when a deposit prepared from water was warmed carefully (Fig. 12c), whereas no hyperfine structure was observed from a sample containing deuterium oxide. The hyperfine structure shows that the electron interacts primarily with six protons and that it is not delocalized over a large number of water molecules but is located in a well-defined trap surrounded by these protons. 

A compound for NMR spectroscopy must be a liquid or solid which can be put in a solution. The usual solvents are deuterochloroform (CDCI3), deuteroacetone (CD3-CO-CD3) or deuterium oxide (D2O). 

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