All-nitrogen species

For the first time in more than 100 years, a new species containing only nitrogen atoms has been discovered. In 1999 chemists Karl O. Christe and William W. Wilson working at Edwards Air Force Base in California reported a compound containing the N5+ cation. The only other all-nitrogen species known are molecular nitrogen (N2), isolated in 1772, and the azide ion (N3 ), first synthesized in 1890. 

With respect to all-nitrogen species (N ), there are only a very few species known that have been isolated and characterized (Table 1). 

All nitrogen fluorides are very reactive, often dangerous species, generally powerful oxidizers. Such compounds as NF3 (5F = +143) and N2F4 would virtually never be encountered in an organic synthesis laboratory, and no NMR data have even been reported for the latter compound. NF3 has a pyramidal structure, with F—N—F bond angles of -102°. 

The synthesis of a further group of co-facial dimers containing all-nitrogen donor atoms have been described (Busch, 1980). For example, Ni(n) species of type (142 with R = -(CH2)2-,-(CH2)2,-(CH2)4, m-xylene, or Cy-fluorene) have been isolated (Busch et al., 1981 Herron et al., 1983) these nickel dimers contain the metal ions in square-planar environments. 

In contrast to nitric oxide, which is firmly identified in biological systems and for which numerous (but not all) functions are known, the participation of other nitrogen species in biological processes is still hypothetical. At present, the most interest is drawn to the very reactive nitroxyl anion NOT It has been shown that nitroxyl (or its conjugate acid, HNO)... 

All positively charged nitrogen species and all organic nitrogen-containing compounds are readily converted to nitrite and then to nitrate in soil. Because of this ready conversion, all are sources of nitrogen for plants. 

Acids of DNCM. The most stable form of DNCM acids is the oxime (Figure 28), while all other species, protonated either at the central C atom (dinitrosocyanomethane dinitrosoacetonitrile) or at the nitrogen of the cyano group, represent high-lying tautomeric isomers. Neither of the acids of DNCM is experimentally known. 

Several vendors offer NO redncing catalyst additives. All have seen commercial success in reducing NO. However, the resnlts have not been consistent. The additives do not function like SO redncing additives that absorb the desired pollutant and transfer it to the reactor. Cnrrent generation NO additives affect the availability of nitrogen species to be oxidized and rednced, which is highly dependent on the bed hydrodynamics. As such, performance depends on the application. 

In order to secure a continuous quantitative analysis of the outlet gas mixture, including all the species necessary for the evaluation of the nitrogen atomic balance, namely NH3, NO, N02 (reactants), N2 and N20 (products), the gases exiting the reactor were analyzed both by a Mass Spectrometer (MS) (Balzers QMS200) and by a UV analyzer (ABB Limas 11HW) in a parallel... 

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