Hydrazide ions

Hydrazinium salts, N2H5 X, are acids in anhydrous hydrazine, metallic hydrazides, N2H, are bases. Neutralization in this solvent system involves the hydrazinium and hydrazide ions and is the reverse of equation 7. Metal hydrazides, formally analogous to the metal amides, are prepared from anhydrous hydrazine and the metals as well as from metal amides, alkyls, or hydrides. (The term hydrazide is also used for organic compounds where the carboxyUc acid OH is substituted with a N2H2.) Sodium hydrazide [13598-47-5] is made from sodium or, more safely, from sodium amide (14) ... 

Analogous reactions have been carried out with hydrazide ions (R2NNH A mixture of NO2 and O3, with excess NaHS03, converted pyridine to 3-aminopyri-dine. ° For other methods of aminating aromatic rings, see 11-6. 

Aziridinium ion-based click chemistry provides convenient access to pyrazolo[l,2-ajpyrazoles, active inhibitors of penicillin-binding proteins [58, 59]. Ring-opening of aziridinium ions 32 at the benzylic position with hydrazine, followed by intramolecular cyclization, gave pyrazolidin-3-ones 37 in excellent yields (Scheme 12.27). Heating of the hydrazides 37 with aromatic aldehydes at reflux in absolute... 

In contrast to the addition products of hydrazines, the interaction of arenediazonium ions with acid hydrazides (Scheme 6-18) yields tetrazenes (6.26), which can be isolated. Tetrazoles (6.27) are obtainable by cyclization (Dimroth and de Mont-mollin, 1910). 

The acyl azide intermediates are prepared either by reaction of sodium azide with a reactive acylating agent or by diazotization of an acyl hydrazide. An especially convenient version of the former process is treatment of the carboxylic acid with ethyl chloroformate to form a mixed anhydride, which then reacts with azide ion.265... 

That a bridged peroxide 68 (for a more detailed discussion, see 1>, p. 84) arises from the intermediate open-chain peroxide formed either by recombination of hydrazide radical ion with. 02( > radical ion, such as 66, or by nucleophilic attack of ion on a carbonyl group of a diazaquinone, such as 67, appears to be very plausible. One of the most important experimental reasons for this assumption has been put forward by E. H. White and M. M. Bursey 106> who, on oxidation of luminol with... 

The importance of radical ions and electron-transfer reactions has been pointed out in the preceding sections (see also p. 128). Thus, in linear hydrazide chemiluminescence (p. 103) or acridine aldehyde or ketone chemiluminescence, the excitation steps consist in an electron transfer from a donor of appropriate reduction potential to an acceptor in such a way that the electron first occupies the lowest antibonding orbital, as in the reaction of 9-anthranoyl peroxide 96 with naphthalene radical anion 97 142> ... 

F. E. Lyttle and D. M. Hercules 161) investigated the energetic relations in the chemiluminescent reaction of ruthenium chelate complexes (Ru-III-2.2 -bipyridyI-, — 5-methyl-1.10-phenanthrolin — and other complexes) with hydroxyl ion or hydrazide. The general reaction is... 

Hydraulic properties, of ion-exchange resins, 74 399 403 Hydraulic retention time (HRT), in biological waste treatment, 25 829 Hydraulic scales, 26 229-230 Hydraulic-settling classifiers, 22 275 Hydrazide(s), 70 504 73 573-576... 

Selection-coupled analysis/phase segregation. One strategy for simplifying the analytical challenge is to use phase segregation. Three subclasses are possible. In the first of these, a phase transition is part of the selection process. This includes not only the familiar crystallization-induced enantiomeric enrichment discussed above but also the experiments (primarily employed in experiments directed toward the production of novel materials) such as those described by Lehn and coworkers in 2005. In this study, an acylhydrazone library was created from guanosine hydrazide and a mixture of aldehydes (Fig. 1.22) in the presence of metal ions, formation of G-quartet structures led to the production of a gel. 

Ogilvie monitored the Diels-Alder reaction between cinnamaldehyde and cyclopentadiene by H NMR using his hydrazide catalyst 18 and was able to conclude that under the reaction conditions adopted (18-TfOH 100 mol% CDjNOj/D O (19 1) 0.1 M) cycloaddition was the rate limiting step of the catalytic cycle, iminium ion formation and hydrolysis being rapid [48]. In addition, it was also shown that under these reaction conditions the key cycloaddition step was reversible. Although this unexpected reversibility was slow, the possibility of exploiting this in a dynamic resolution procedure appears tempting. 

X-Ray crystal structures of the MacMillan imidazolidinones 12 HC1 and ent-12"HC1 have been reported [228], Iminium ions derived from a hydrazide [47] and trifluoromethyl pyrrolidine [227] have also been characterised through crystallography. 

The magnitude of K value for this self-ionization is in the order of which is greater than that for anhydrous ammonia ionizing to ammonium (NR4+) and amide (NH2 ) ions (K 10-33). Anhydrous hydrazine thus forms salts with hahde and other anions of the composition N2H5 X which are acids. Similarly, metallic hydrazides, M N2H3, are bases in anhydrous hydrazine. Most hydrazine salts are unstable and are sensitive to heat and... 

Monomeric dialkylaluminum hydrazides with terminal hydrazido groups (A, Scheme 2) were observed only in those cases in which donor ligands such as ether molecules (28 to 30) or hydride ions (26) saturate the aluminum atoms to yield coordination numbers of four. In the absence of Lewis bases dimers are formed of the monoaluminum and monogallium monohydrazido derivatives, a trimer has never been detected by crystal structure determinations. Three different types of structures were reported ... 

If the cation introduced by ion exchange is capable of multiple valence, the clay may serve as a catalyst for oxidation or reduction reactions. For example, montmorillonite treated with iron(III) nitrate is so reactive that it has to be stored under an inert atmosphere the clay catalyzes reactions of the nitrate ion, such as oxidation of secondary alcohols to ketones (via nitrite ester intermediates) and organic hydrazides to azides, and the nitration of phenols. 

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