Synthesis and characterization of the pentazolate anion cyclo -N 5 ˉ in (N 5 ) 6 (H 3 O) 3 (NH 4 ) 4 Cl

A salty route to an all-nitrogen ring The flip side of the robust stability of N 2 is the instability of any larger molecules composed exclusively of nitrogen. These molecules nonetheless remain enticing targets for explosive and propellant applications. Zhang et al. successfully prepared the pentazolate ion, a negatively charged ring of five nitrogens, by oxidative cleavage of a C–N bond in an aryl-substituted precursor (see the Perspective by Christe). The molecule was stabilized and isolated in the solid state as a hydrated ammonium chloride salt. Spectroscopic and crystallographic characterization confirmed the ring’s planar geometry. Science , this issue p. 374 ; see also p. 351