4,4′-Bis(nitramino)azofurazan and its salts. Study of molecular and crystal structure based on X-ray and quantum chemical data

Abstract

4,4´ Bis(nitramino)azofurazan 2 was obtained by nitration of 4,4 diaminoazofurazan 1. Molecular and crystal structure of nitramine 2 and its ammonium salt 3 were studied by X ray method and quantum chemical calculations at M052X/aug cc pvdz level of theory. Both com pounds adopt ap ap ap conformation. It was shown that the structure of furazan cycle signifi cantly depends on the nature of the substituents at carbon atoms. Crystal structures of 2 and 3 are characterized by sufficiently high density (1.996 and 1.832 g cm -3 at 110K and 1.919 and 1.766 g cm -3 at 295 K, respectively), which is provided, in particular, by strong intermolecular hydrogen bonding and π-π stacking interactions. Among substituted azofurazans and primary nitramines examined by X ray diffraction analysis, 4,4´ bis(nitramino)azofurazan 2 is charac terized by the highest density.

Synthesis of 3‐(3,5‐dinitropyrazol‐4‐yl)‐4‐nitrofurazan and its salts

“…Geometry optimization was carried out at M052X/aug‐cc‐pvdz level of approximation by the GAUSSIAN03 program [18]. This level of approximation was succesfully utilized in our recent study on structural peculiarities of nitraminofurazans [19]. As initial geometry, we used X‐ray one as well as a geometry in which two 5‐membered rings are coplanar while nitro groups are oriented perpendicular.…”

“…Combination of the electron‐withdrawing furazan ring with moieties containing acidic proton increases its acidity. Recently, a number of furazan‐based acids was synthesized and utilized as anions for a preparation of energetic salts [19, 23].…”

Synthesis and investigation of isomeric mono- and dinitro derivatives of 3-methyl-4-(pyrazol-3-yl)furazan

“…68 2)) = 0.002 Å). In accordance with this, the relative electron-withdrawing properties of isomeric nitropyrazole moieties decreased in the series: 1-nitro-> 3(5)-nitro-> 4-nitro substituent.…”

“…For in-depth structural analysis we performed quantum-chemical calculations for compound 5 with the GAUSSIAN software, 60 using the M052X/aug-cc-pvdz approximation, that was successfully used earlier for description of π-conjugated heterocyclic systems. 61 68 but, crucially, the difference of N-O bond lengths was modelled correctly. According to calculations, a planar structure for molecule 5 should be optimal, since it lacks intramolecular steric strains.…”

Synthesis and crystal structure of trinuclear potassium(I) complex with oxy-bridged bis(gem-dinitro)furazan and triaminoguanidinium

“…The combination of nitrogen-rich furazan ring with energetic group or backbones containing acidic protons could serve as anions to form energetic compounds. In this regard, compounds such as, nitramine or tetrazole-functionalized based furazan had been investigated and were found to have shown promising performance [7][8][9][10][11][12]. The gem-dinitro group has been reported as being an effective anion to construct gem-dinitro group containing energetic compounds, with the high value of density contribution of 1.759 g cm -3 [13][14][15].…”