Energetic
High-Nitrogen Compounds: 5‑(Trinitromethyl)‑2<i>H</i>‑tetrazole and -tetrazolates, Preparation, Characterization,
and Conversion into 5‑(Dinitromethyl)tetrazoles
- Publication date
- Publisher
Abstract
A convenient access to 5-(trinitromethyl)-2<i>H</i>-tetrazole
(HTNTz) has been developed, based on the exhaustive nitration of 1<i>H</i>-tetrazole-5-acetic acid, which was prepared from ethyl
cyanoacetate and HN<sub>3</sub> in a 1,3-dipolar cycloaddition reaction,
followed by basic hydrolysis. HTNTz was converted into the ammonium,
guanidinium, rubidium, cesium, copper, and silver 5-(trinitromethyl)-2<i>H</i>-tetrazolates. In addition, the ammonia adducts of the
copper and silver salts were isolated. The reaction of HTNTz with
hydrazine and hydroxylamine resulted in the formation of hydrazinium
5-(dinitromethyl)tetrazolate and hydroxylammonium 5-(dinitromethyl)-1<i>H</i>-tetrazolate, respectively. Acid treatment of both 5-(dinitromethyl)tetrazolates
resulted in the isolation of 5-(dinitromethylene)-4,5-dihydro-1<i>H</i>-tetrazole, which was converted into potassium 5-(dinitromethyl)-1<i>H</i>-tetrazolate by reaction with K<sub>2</sub>CO<sub>3</sub>. All prepared compounds were fully characterized by <sup>1</sup>H, <sup>13</sup>C, <sup>14</sup>N, and <sup>15</sup>N NMR spectroscopy
and X-ray crystal structure determination. Initial safety testing
(impact, friction, and electrostatic sensitivity) and thermal stability
measurements (differential thermal analysis, DTA) were also carried
out. The 5-(trinitromethyl) and 5-(dinitromethyl)tetrazoles are highly
energetic materials that explode upon impact or heating