Sodium pentazolate: A nitrogen rich high energy density material

Abstract

Sodium pentazolates NaN 5 and Na 2 N 5 , new high energy density materials, are discovered during first principles crystal structure search for the compounds of varying amounts of elemental sodium and nitrogen. The pentazole anion (N − 5 ) is stabilized in the condensed phase by sodium Na + cations at pressures exceeding 20 GPa, and becomes metastable upon release of pressure. The sodium azide (NaN 3 ) precursor is predicted to undergo a chemical transformation above 50 GPa into sodium pentazolates NaN 5 and Na 2 N 5 . The calculated Raman spectrum of NaN 5 is in agreement with the experimental Raman spectrum of a previously unidentified substance appearing upon compression and heating of NaN 3 .

Pentazole and Ammonium Pentazolate: Crystalline Hydro-Nitrogens at High Pressure

“…High pressure substantially modifies the potential energy surface thus promoting unusual chemical bonding in the condensed phase. Recently, several N 5 -ring containing crystals have been predicted [12][13][14] and one of them, CsN 5 , has been synthesized at high pressures 15 .…”

Confinement of the Pentanitrogen Cation Inside Carbon Nanotubes

“…Most notably, the cubic gauche polymeric nitrogen form was successfully synthesized a few years ago under very high temperature and pressure [13]. In recent years, different PN clusters and molecular crystals were theoretically predicted and some were experimentally obtained [14][15][16][17][18][19][20]. In 2017, two main achievements renovated once again the interest in the field, namely the isolation and characterization of cyclo-N − 5 pentazolate [21] and the synthesis of the cubic gauche form of nitrogen under near-ambient conditions [22].…”

Structural phase transition and bonding properties of high-pressure polymeric CaN3

“…Recently, metal azides can be used as the starting materials to synthesize numerous types of potential high-energy-density materials because the synthesis pressure of metal azides is potentially lower than that of pure nitrogen gas. Over the years, various metal azides have been proposed in numerous experimental and theoretical studies, for example, LiN 3 , [13][14][15][16] LiN 5 , 13 NaN 3 , [17][18][19][20][21] KN 3 , 20,[22][23][24][25][26][27] CsN 3 , 23,28 and AlN 3 . 29 Moreover, N 2 H, 30,31 C-N system, 32,33 S-N system, 34 and the P-N system 35 are also studied as high-energy materials.…”