Hyponitrite anion

The N-N-bonded hyponitrite anion [0-N=N-0] can be accessed via the following solution-phase synthesis ... 

Suggest a mechanism for the process. (The hyponitrite anion can exist as either cis or trans isomers. The cis isomer serves as a chelating ligand for metal ions.)... 

Oxygen-centered radicals are arguably the most common of initiator-derived species generated during initiation of polymerization and many studies have dealt with these species. The class includes alkoxy, hydroxy and aeyloxy radicals and tire sulfate radical anion (formed as primary radicals by homolysis of peroxides or hyponitrites) and alkylperoxy radicals (produced by the interaction of carbon-centered radicals with molecular oxygen or by the induced decomposition of hydroperoxides). 

A transient feature at approximately 1154 cm-1 occurred in some spectra and apparently represents an adsorbate which is unstable between 120 K and 180 K on Ru(001). In several cobalt complexes, the presence of the hyponitrite ligand, N202, is characterized by infrared bands between 925 and 1195 cm-1, depending upon the nature of the anion and other ligands (46,52,53). The exact identity of this transient species on the Ru(001) surface will require further clarification, however. 

HJ and starch action. As HJ and starch are poured into a potassium hyponitrite solution, the latter is colored blue 2-3 min afterwards, which is a result [171, 172] of insignificant amounts (traces) of N02 anion presence, which were formed in the following reaction [171-174] ... 

The silver salt is precipitated from aqueous solutions by AgN03. In the solid state the hyponitrite ion has been found in the cis conformation (9-IX) the trans ion has been reported but its existence has been questioned. The anion is stable in water but is decomposed by dilute acid. Protonation on only one oxygen atom... 

NO reduction activity has been observed to be enhanced by contacts between the metal and ceria.15,20 This is interpreted through a somewhat similar mechanism, in which metal-adsorbed NO dissociates at the metal-oxide interface, probably by interacting with anion vacancy sites produced by previous reduction at the ceria surface, transferring the O atom to the oxide, which is thus reoxidised. It should be mentioned, however, that some NO reduction can occur also in the absence of metal on a reduced ceria surface,21 leading to N20 production and ceria reoxidation through formation of an intermediate hyponitrite species. 

The nitroxyl anion dimerizes to form hyponitrite 2NO------------------------------ NzOz -... 

The simultaneous formation of nitrites and hyponitrites can be imderstood on the basis of the redox properties of Ce ions. Thus nitrites may form when NO is adsorbed on Ce " " ions with anion vacancies in their coordination spheres, leading to reduction of the cerium cation ... 

Part of these N2O2" groups may be unstable at 295 K and decompose to produce N2O (that can remain adsorbed or desorbe into the gas phase) and 0 anions close to the reoxidized cerium cations. Since N2O is observed in coincidence with the cis type of N202° species, it seems probable that these latter are mor unstable and reactive than those of the trans kind. The fact that such hyponitrites (and subsequently N2O) can be detected for Tv lower than that necessary to observe... 

NiO. This oxide has been prepared in a dispersed high-area form by decomposition of the hydroxide. By interaction with NO, nitrosilic species are formed on surface cations, while by interactions with anions, mainly nitrite and hyponitrite species are observed. The species formed upon CO contact are very similarin that surface carbonylic species and bidentate carbonates are simultaneously formed. Moreover these two surface species are in close proximity on the surface. 

The thermal decomposition of solid alkali metal trioxodinitrates is suggested to involve the intermediate formation of hyponitrite. The N nmr spectrum of the trioxodinitrate anion shows that protonation occurs at the nitrosyl nitrogen atom as in equation (12). This observation has... 

A new series [32] of electron transfer initiators has been shown to give rise to long-lived oxygen-centered radical species attached to propagating acrylate and methacrylate chain ends. The long-lived nature of these chain ends makes it possible to prepare block copolymers in some cases. The oxygen-centered radical species are generated from hyponitrite, arenediazoate, or cyanate anions by reaction with electron acceptors such as arenediazonium ions or activated alkyl halides. 

Kornblum [33] showed that suitably activated alkyl halides undergo facile electron transfer when reacted with anions such as (CH3)2C(N02), CgHsS, N3, and l-methyl-2-naphathoxide. /V-Halosuccinimides also react with arenediazoate, hyponitrite, or cyanate anions in the presence of monomer to initiate polymerization, presumably in analogy to the reactions using arenediazonium ions ... 

The second method involves one-electron oxidation of arenediazoate, hyponitrite, or cyanate anions by reaction with arenediazoazodiazonium ions. Aryl radicals then initiate polymerization [32] of the monomer/methyl methacrylate, and the corresponding stabilized oxyl radical is associated with the growing end of the poljrmer ... 

Thus it is the conjugate acid of the anion which actually undergoes decomposition. cw-Hyponitrite ion is a suggested intermediate. The activation parameters... 

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