N5+: A Novel Homoleptic Polynitrogen Ion as a High Energy Density Material.

Only the third known example of a homoleptic polynitrogen species besides N2 and N3−, the N5+ ion possesses surprising stability and can be isolated on a macroscopic scale as its AsF6− salt. The assigment of the C2v-symmetric structure (shown schematically) predicted by calculations was supported by IR and Raman as well as 14N and 15N NMR spectroscopic studies of the isotopically labeled product.