Deuterated salt

FIGURE 8.2 Structure factors S(QZ) obtained from neutron-scattering patterns of butylam-monium vermiculite gels (upper panels) and from a 0.1 M protonated butylammonium salt solution with no clay (lowest panel). The upper panels show S(QZ) for gels prepared in a 0.1 M deuterated salt solution and in 0.1 and 0.01 M protonated salt solutions. The momentum transfer Q was perpendicular to the clay plates, and the structure factor S(QZ) has been normalized after correction for background scattering and absorption. 

Diselenoniabicyclo[3.3.0]octane hexafluorophosphates were prepared by reaction of 1,5-diselenacyclooctane with nitronium hexafluorophosphate <89CC1789, 90TL6375). 2,2,8,8-Tetra-deuterated salts have also been synthesized <93T1605>. 

Figure 4. (a) INS spectra of the deuterated salt of the [Co3W(D20)2(CoWc 034)2] polyanion mesured on the INS spectrometer with an incident neutron scattering of 4.1 A at 1.5,10 and 30 K. (b) Energy level diagram of the C05 cluster derived from the INS experiments. 

Wittig reactions of deuterated salts (e.g. 171) have been used as building blocks in the synthesis of a variety of deuterium-labelled Lepidoptera pheromones and analogues. The main component (175) of the sex pheromone of the green stink hugNezara viridula has been synthesised by phosphine oxide-based olefination of the ketone (172) (Scheme 18). The initial reaction gives... 

Table 9.2 An example of the change in structural data through deuteration. Non-deuterated (2,5-dimethyl-DCNQI)2Cu (do, curve la in Fig. 9.15)is compared to the 6-fold-deuterated salt (in its two methyl groups dg, curve Ic in Fig. 9.15). From [16]. Here, a and c are the lattice constants and V ll is the volume of the unit cell. It contains...

A whole series of salts MH2PO4 and MH2ASO4 are known, where M = K, NH4, Rb, Cs, Tl. Most of these are isomorphous with KH2PO4 and show piezoelectric, ferroelectric and other interesting properties. Deuterated salts such as KD2PO4 are also well characterised (Tables 12.52 and 12.53). 

The isotope effect on by replacing H atoms of methyl groups of TMTSF by deuterium was studied on the CIO4 salt and the results are not settled. One result indicates that there is no isotope effect within the experimental error, while the other suggests that the deuterated salt with TMTSF-djj (MW 454) has a lower (T = 0.95 K) than that of the nondeuterated salt (T = 1.08 K). The direction of lowering... 

During the formation of ylide 2 in the presence of EtOLi the acetate moiety has been lost. As the reagent is a nucleophile, it is reasonable to consider that the removal of the acetate group takes place by a classical addition-elimination process induced by ethoxide. Thus, nucleophilic attack of the EtOLi on the carboxylate in 1 would form intermediate 11 that by elimination of ethyl acetate gives ylide 2 (Scheme 31.5). This mechanistc proposal is fully in agreement with the retention of the deuterium label in the reaction products 10 when starting from the a-deuterated salt 9. 

Pyrazolino[2,3-c][l,2,3]triazoles, 5, 702 Pyrazolium hydroxide, l,2-dimethyl-3,5-diphenylanhydro-4-hydroxy-IR spectra, 5, 201 Pyrazolium salts dequatemization, 5, 269 H NMR, 5, 185 hydrogen exchange at ring carbon, 5, 245 mesoionic compounds, 5, 171 nitrodebromination, 5, 237 reactivity, 5, 217 reduction, 5, 68, 243 synthesis, 5, 156 UV spectra, 5, 199 Pyrazolium salts, amino-reactions, 5, 262 Pyrazolium salts, bromo-nucleophilic displacements, 5, 266 Pyrazolium salts, 1,2-dimethyl-deuteration, 5, 175, 245 hydrogen exchange, 5, 71 acid-catalyzed, 5, 239 reactions... 

Pyrylium salts, 2,3,4,6-tetramethyl-synthesis, 3, 868 Pyrylium salts, 2,4,6-trialkyl-oxidation, 3, 650 Pyrylium salts, 2,4,6-triaryl-synthesis, 3, 870 Pyrylium salts, 2,4,6-trimethyl-deuteration, 3, 649 synthesis, 3, 861, 868, 873 Pyrylium salts, 2,4,6-trimethyl-4-styryl-reactions... 

The mechanism suggested earlier for the similar isomerization 34 35 involving the reaction of a 1,2-dihydroquinoline molecule with the starting quinolinium salt 33 (Scheme 11) is analogous to that of 4//-thiopyran isomerization discussed above (cf. Scheme 3) and is supported by deuterated substrate studies (85CJC412). Further support for this mechanism is the absence of such isomerization for 4-substituted derivatives such as 1,4-dimethyl-1,2-dihydroquinoline [94JCS(CC)287]. 

In general, isotopic exchange is both expensive and difficult. In the case of many room-temperature ionic liquids, however, the manufacture of deuterated ionic liquids is relatively easily achievable. For example, the general synthesis of l-allcyl-3-methylimidazolium salts is shown in Scheme 4.1-1 [2]. This methodology allows maximum flexibility in the deuteration on the imidazolium cation that is, it can be either ring or side chain deuteration or both. 

Hardacre et al. have developed a procedure for the synthesis of deuterated imidazoles and imidazolium salts [65]. The procedure involves the platinum- or palladium-catalyzed deuterium exchange of 1-methyl-d -imidazole with D2O to give 1-methylimidazole-d , followed by treatment with a deuterated alkyl halide. 

A salt effect similar to that reported for the deuteration of methyl benzyl sulfoxide (see Section D. 1.1.1.5.) was also shown in this case (Table 2). 

In the early 1960s it was shown that the anion B10H 0 " acts as a reactive substrate in electrophilic substitutions such as halogenations, alkylations, nitrosations, and deuterations (see Housecroft, 1990, Figs. 7.3.1 and 7.3.2). Therefore Hawthorne and Olsen (1964, 1965) investigated the reactivity of this anion with a series of unsubstituted and substituted benzenediazonium salts. In aqueous solution yellow and... 

Specifically deuterated ylides (16) and bromoalkylphosphonium salts (17) (and the corresponding ylides (18)) have been prepared by... 

As we have already mentioned, CDCI3 should be avoided as a solvent for salts for two reasons. Firstly, salts are unlikely to be particularly soluble in this relatively nonpolar solvent but more importantly, spectral line shape is likely to be poor on account of relatively slow proton exchange at the protonatable centre. The remedy is simple enough - avoid using CDCI3 and opt for one of the more polar options instead, e.g., deuterated DMSO or MeOH and you should obtain spectra every bit as sharp as those of free bases. 

Protons are easily detached from the furan nucleus, especially when some activating group is present. Even the carbonate ion will catalyze the deuter-ation of position 5 in 2-furoic acid salt.177 And 40% NaOD in D20, will catalyze the replacement of all the nuclear protons giving the fully deuterated product. The acid can be converted into d4-furan by treatment with mercury salts, and then DC1.178 For general synthetic purposes it is now usual to obtain nuclear carbanions by lithiation as described in Section IV. 

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