RT Journal Article
SR Electronic
T1 Synthesis and characterization of the pentazolate anion cyclo-N5ˉ in (N5)6(H3O)3(NH4)4Cl
JF Science
JO Science
FD American Association for the Advancement of Science
SP 374
OP 376
DO 10.1126/science.aah3840
VO 355
IS 6323
A1 Zhang, Chong
A1 Sun, Chengguo
A1 Hu, Bingcheng
A1 Yu, Chuanming
A1 Lu, Ming
YR 2017
UL http://science.sciencemag.org/content/355/6323/374.abstract
AB The flip side of the robust stability of N2 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. 351Pentazole (HN5), an unstable molecular ring comprising five nitrogen atoms, has been of great interest to researchers for the better part of a century. We report the synthesis and characterization of the pentazolate anion stabilized in a (N5)6(H3O)3(NH4)4Cl salt. The anion was generated by direct cleavage of the C–N bond in a multisubstituted arylpentazole using m-chloroperbenzoic acid and ferrous bisglycinate. The structure was confirmed by single-crystal x-ray diffraction analysis, which highlighted stabilization of the cyclo-N5ˉ ring by chloride, ammonium, and hydronium. Thermal analysis indicated the stability of the salt below 117°C on the basis of thermogravimetry-measured onset decomposition temperature.