Energetic Bis(3,5-dinitro-1H-1,2,4-triazolyl)dihydro- and dichloroborates and Bis(5-nitro-2H-tetrazolyl)-, Bis(5-(trinitromethyl)-2H-tetrazolyl)-, and Bis(5-(fluorodinitromethyl)-2H-tetrazolyl)dihydroborate

Abstract

Salts of bis(3,5-dinitro-1H-1,2,4-triazolyl)dihydro- and dichloroborate and bis(5-nitro-2H-tetrazolyl)-, bis(5-trinitromethyl-2H-tetrazolyl)-, and bis(5-fluorodinitromethyl-2H-tetrazolyl)dihydroborate anions have been synthesized by the treatment of hydroborates or chloroborates with the corresponding nitroazoles or nitroazolates, respectively. Alkali-metal salts of these dihydroborates are energetic and can be shock-sensitive, while salts with larger organic cations, such as NMe4(+), PPh4(+), or (Ph3P)2N(+), are less sensitive. Poly(nitroazolyl)borates are promising candidates for a new class of environmentally benign energetic materials and high-oxygen carriers.

Synthesis and Characterization of Nitro‐, Trinitromethyl‐, and Fluorodinitromethyl‐Substituted Triazolyl‐ and Tetrazolyl‐trihydridoborate Anions

“…The relative proximity of the nitro groups in neighboring [TNMeTz‐BH 3 ] − anions (O6⋅⋅⋅O6 distance of 2.860(2) Å) and the relative instability of compounds 6 / 7 suggests that this distortion of the N6 nitro group might be an actual feature of the anion and not a disorder refinement artifact. As found for trinitromethyltetrazole and [BH 2 (TNMeTz) 2 ], the N‐substitution occurs at the position β to the ring‐carbon atom.…”

“…The addition of BH 3 thus results in a slight widening of the N1‐N2‐N3 angle and a slight compression of the N2‐N3‐N3 angle . In contrast to the [Trz‐BH 3 ] − salts, the B−N bond lengths in [Tz‐BH 3 ] − (1.579(5)–1.583(2) Å) are for all practical purposes identical to those observed in [BH 2 (Az) 2 ] − , suggesting a more covalent B−N bond in [Tz‐BH 3 ] − than in [Trz‐BH 3 ] − .…”

“…117°) . The B−N bond lengths in [Trz‐BH 3 ] − range between 1.585(12) and 1.608(4) Å, somewhat longer than the B−N bond lengths in [BH 2 (Az) 2 ] − , which range between 1.572(2) and 1.586(3) Å …”

“…One of the reasons for this was the experimental difficulty to restrict the hydrogen elimination in the [BH 4 ] − /azole systems exclusively to mono‐substitution. Although the reaction of [BH 4 ] − with two equivalents of the free nitro‐, (trinitromethyl)‐ or (fluorodinitro‐methyl)‐substituted azoles (H‐Az) has been successfully applied to the synthesis of several [BH 2 Az 2 ] − salts, the reaction of a single equivalent of the azole with [BH 4 ] − yielded only mixtures of [BH n Az 4− n ] − salts ( n =2, 3) (see Supporting Information). The bis(triphenylphosphoranylidene)ammonium ([PPN] + ) and/or tetraphenylphosphonium ([PPh 4 ] + ) salts of the mono(azolyl)borate anions, [Az‐BH 3 ] − , were therefore prepared by the addition of the [Az] − anion to BH 3 , using an excess (1.2 to 1.5 equivalents) of either BH 3 ⋅S(CH 3 ) 2 in S(CH 3 ) 2 solution or of commercially available BH 3 ⋅THF solutions in THF as the BH 3 sources.…”

Crystal Structures of Some Trinitromethyl Derivatives of 1,3,5-Triazine

“…Ɉɞɧɚ ɢɡ ɩɪɢɱɢɧ ɬɚɤɨɝɨ ɜɧɢɦɚɧɢɹ ɫɨɫɬɨɢɬ ɜ ɜɨɡɦɨɠɧɨɫɬɢ ɫɨɡɞɚɧɢɹ ɧɚ ɢɯ ɨɫɧɨɜɟ ɧɨɜɵɯ ɦɨɳɧɵɯ ɷɧɟɪɝɨɟɦɤɢɯ ɤɨɦɩɨɡɢɰɢɣ [ 7 ]. Ɉɞɧɚɤɨ ɞɚɧɧɵɯ ɨ ɫɬɪɭɤɬɭɪɟ ɩɨɥɢɚɡɨɬɢɫɬɵɯ ɝɟɬɟɪɨɰɢɤɥɢɱɟɫɤɢɯ ɫɨɟɞɢɧɟɧɢɣ ɫ ɬɪɢɧɢɬɪɨɦɟɬɢɥɶɧɵɦɢ ɝɪɭɩɩɚɦɢ ɜ ɥɢɬɟɪɚɬɭɪɟ ɫɪɚɜɧɢɬɟɥɶɧɨ ɧɟɦɧɨɝɨ [8][9][10][11][12][13][14][15][16][17][18][19]. ɋɜɟɞɟɧɢɹ ɨ ɫɬɪɭɤɬɭɪɟ ɦɨɥɟɤɭɥ ɧɟɨɛɯɨɞɢɦɵ ɞɥɹ ɭɬɨɱɧɟɧɢɹ ɫɜɨɣɫɬɜ ɢɡɜɟɫɬɧɵɯ ɢ ɩɪɨɝɧɨɡɢɪɨɜɚɧɢɹ (ɩɥɨɬɧɨɫɬɶ, ɱɭɜɫɬɜɢɬɟɥɶɧɨɫɬɶ, ɬɟɪɦɢɱɟɫɤɚɹ ɫɬɚɛɢɥɶɧɨɫɬɶ, ɞɪɭɝɢɟ ɫɜɨɣɫɬɜɚ) ɟɳɟ ɧɟ ɩɨɥɭɱɟɧɧɵɯ ɷɧɟɪɝɨɟɦɤɢɯ ɫɨɟɞɢɧɟɧɢɣ [ 20 ].…”