Radical ions matrix isolation

It is interesting to note that the catalysts that show good selectivities at the higher temperatures generally do not contain easily reducible metal ions, such as V, Mo, or Sb. Many of the catalysts for the lower-temperatures operation, on the other hand, contain these reducible cations. In a study using a Li-Mg oxide, it was established that gas-phase ethyl radicals could be generated by reaction of ethane with the surface at about 600°C (17). These radicals could be trapped by matrix isolation and identified by electron spin resonance spectroscopy. 

Even though theoretical studies have identified a number of potentially metastable structures [1, 2], the experimentally observed nitrogen compounds are still few. The azide anion, N3, wai. first synthesized in 1890 by Curtius [3]. Christie and coworkers have since 1999 reported the preparation and isolation of Ns"1" together with several different counter ions [4, 5]. A few other species, such as N3, Ns+, N4+, and N6, have been observed only as gaseous or matrix-isolated ions or radicals [6-12], We recently reported the detection of cyclic N5 in a mass spectrometry experiment [13], This observation has later been verified by Christie et. al. in a more elaborate study [14], The experimental preparation and detection of an open-chain N4 molecule was reported in 2002 by Cacace et al [15]. This species is expected to be unstable towards bimolecular decomposition and also too low in energy to be of any greater interest as a HEDM. 

N+ and N+, have been observed only as free gaseous or matrix-isolated ions or radicals. The only polynitrogen species synthesized on a macroscopic scale thus far is the pentanitrogen cation Nj by Christe and co-workers in 1999. 

Practically all experiments showed a case of three-axis anisotropy in EPR spectra, and the EPR parameters could be easily measured. Free radicals in the atmosphere could be detected by a method of matrix isolation and EPR suggested in [93]. Formation of the N022 ion-radical has been proved by using 15NO at the same g-values Az for 15N022 was equal to 54 G instead of 38 G for 14N022 [91]. One can also see from Fig. 2 in [91] that... 

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