Selective Preparation of 3,4,5‐Trinitro‐1H‐Pyrazole: A Stable All‐Carbon‐Nitrated Arene

Abstract

Pernitriert: 3,4,5‐Trinitro‐1H‐pyrazol (TNP, siehe Bild) ist das unerwartete Produkt der Nitrierung von 3,5‐Dinitropyrazol mit einem starken Elektrophil, das aus 20–30 % Oleum und Salpeteräure entsteht. TNP ist bemerkenswert stabil, weil die Ringstruktur erhalten bleibt und die Konformation der Nitrogruppe an C4 die Acidität des Materials in Grenzen hält.

3,4,5‐Trinitropyrazole‐Based Energetic Salts

“…Based on the measured densities and calculated heats of formation, the detonation performances (pressure: 23.74-31.89 GPa; velocity: 7586-8543 ms À1 ; Cheetah 5.0) of the 3,4,5-trinitropyrazolate salts are comparable with 1,3,5-triamino-2,4,6-trinitrobenzene (TATB; 31.15 GPa and 8114 ms rearrangement of N-nitropyrazole in benzonitrile, amination with 1,1,1-trimethylhydrazinium iodide, and finally oxidation with 30 % hydrogen peroxide (Scheme 1). [11,12] Reactions of HTNP with ammonia, triA C H T U N G T R E N N U N G azole, 3-aminotri-A C H T U N G T R E N N U N G azole, 4-aminotrizole, 3,5-diaminotriazole, guanidine carbonate, aminoguanidine bicarbonate, and 3,6-diguanidinotetrazine, resulted in the formation of salts 1-8 (Scheme 2). Other salts 9-14 were readily synthesized by metathesis reactions of 3,4,5-triaminotriazolium chloride, 1,4-dimethyl-5-aminotetrazolium, and 1,5-diamino-4-methyltetrazolium iodides, and diaminoguanidium and triaminoguanidinium chlorides with AgA C H T U N G T R E N N U N G (TNP) (or AgA C H T U N G T R E N N U N G (TNI), silver trinitroimidazolate), which was obtained from treatment of KTNP (or KTNI) with an equivalent amount of aqueous silver nitrate.…”

“…When the decomposition peak in the DSC scan was not sharp, the salts were examined by using thermogravimetric analysis (TGA). While salts 1 and 8 decomposed without melting at 224 and 243 8C, respectively, the other salts have melting and decomposition temperatures ranging from 120 (11) to 206 8C (9) and 167 (2 and 11) to 243 8C (8). Densities for the TNP salts were measured with a gas pycnometer, and found in the range between 1.61 (10) and 1.77 g cm À3 (4).…”

“…The heats of formation (DH f ) of the TNP salts are calculated by using Born-Haber energy cycles (see the Experimental Section). They are positive, and fall in the range 0.11 (6) to 1.45 kJ g À1 (11). With the data of density, heat of formation, and oxygen balance in hand, the detonation pressure (P) and velocity (vD), and specific impulse (I sp ) values of the TNP salts were calculated with Cheetah 5.0.…”

“…3,4,5-Trinitropyrazole with a calculated density of 1.867 g cm À3 is stable up to 200 8C, making its salts potential energetic materials. [10,11] However, 3,4,5-trinitropyrazolate salts were only mentioned in patents without characterization and properties. [10] In our work, a series of high-nitrogen 3,4,5-trinitropyrazolate salts have now been prepared and characterized.…”

4‐Nitramino‐3,5‐dinitropyrazole‐Based Energetic Salts

“…[9] Among them, the pyrazole-based nitroazoles have been extensively investigated. In addition to 3,4,5-trinitropyrazole, [10,11] its dinitro-derivatives, such as 4-amino-3,5-dinitropyrazole, [12] 5-amino-3,4-dinotropyrazole, [11] 5-azo-3,4-dinitropyrazole, [11] 5-nitramino-3,4-dinitropyrazole, [13] have been reported. Based on our calculations, another dinitro-derivative of pyrazole (the unknown 4-nitramino-3,5-dinitropyrazole), with a calculated density of 1.97 g cm…”