A Comparative Study on Insensitive Energetic Derivatives of 5‐(1,2,4‐Triazol‐C‐yl)‐tetrazoles and their 1‐Hydroxy‐tetrazole Analogues

Abstract

The synthesis and characterization of selected nitrogen‐rich salts based on 5‐(1,2,4‐triazol‐C‐yl)tetrazoles and their 1‐hydroxy‐tetrazole analogues is presented. The combination with guanidinium, triaminoguanidinium, and hydroxylammonium cations leads to enhanced performance and sensitivities. The main focus of this work is on the energetic properties of those ionic derivatives in comparison to the neutral compounds. Additionally, the positive influence of the introduction of N‐oxides in energetic materials is shown. Structural characterization was accomplished by means of Raman, IR, and multinuclear NMR spectroscopy. The standard enthalpies of formation were calculated for selected compounds at the CBS‐4M level of theory, the detonation parameters were calculated using the EXPLO5.05 program. Additionally, thermal stability was measured via DSC and sensitivities against impact, friction, and electrostatic discharge were determined.

Combining Performance with Thermal Stability: Synthesis and Characterization of 5‐(3,5‐Dinitro‐1H‐pyrazol‐4‐yl)‐1H‐tetrazole and its Energetic Derivatives

“…The bond lengths within the azole rings are between the expected values for C-C, C-N and N-N single and double bonds (C-C:1.47 Å, 1.34 Å, C-N: 1.47 Å, 1.22 Å; N-N: 1.48 Å, 1.20 Å). [36][37] The C-C bond between the two aromatic rings has the classic length of a single bond (C2-C4 1.465 Å) [36,38] (Figure 2 ties in the ac plane form a strong intramolecular interaction with N8 at the tetrazole of the adjacent unit through the hydrogen at the pyrazole (N1-H1•••N8 iii , 1.90 Å). The steric demand of the nitro groups also explains the tilting of the aromatic rings towards each other in the layering.…”

Combining the Advantages of Tetrazoles and 1,2,3‐Triazoles: 4,5‐Bis(tetrazol‐5‐yl)‐1,2,3‐triazole, 4,5‐Bis(1‐hydroxytetrazol‐5‐yl)‐1,2,3‐triazole, and their Energetic Derivatives

“…Additionally,t he 15 NN MR spectra of 6 and its ammonium salt 6b were recorded and are de-picted in Figure 1. The assignments are based on comparison with similarm olecules [19] in addition to theoretical calculations using Gaussian09[ OP86/SVP NMR scrf = (solvent = dmso)]. [20] The resonances corresponding to the triazole nitrogen atoms of 6 and 6b could be assigned, due to their coupling with the hydrogen atom, to the peaks at d = À54.9 (N5) and À100.3 ppm (N6) in 6 and at d = À32.7 (N6) and À49.6 ppm (N5) in 6k,r espectively.T he signal correspondingt ot he nitrogen carrying the hydroxy group is shifted by deprotonation from d = À116.1 to À86.8 ppm.…”

“…The bond lengths and angles within the azole rings are all within the range of formal CÀN, NÀN, and CÀCs inglea nd double bonds( C ÀN: 1.34, 1.33 ; CÀC: 1.41 ; NÀN: 1.36, 1.30 ) [3,21] andi nt he same range as the correspondingb onds of the non-deprotonated azole rings of the dimethylammonium salt of 2.T he NÀO bond length of 1.3515 (18) i ss lightly elongated in comparison to other tetrazole N-hydroxy bond lengths (mean length: 1.34 ). [19,22] The N-hydroxy protons participate in as trongly directed hydrogen bond to the crystal water with an O1ÀH1···O2 angle of 1728 (Table 3). Furthermore, the same orientation of the N-hydroxy group and the triazole ring leads to aw eaki ntramolecular N5···O1 interaction of 3.030(2) , within the sum of the van der Waals radii[ r w (O) + r w (N) = 3.07 ].…”

Ionic binuclear ferrocenyl compounds containing 1,1,3,3-tetracyanopropenide anions – synthesis, structural characterization and catalytic effects on thermal decomposition of main components of solid propellants

“…In our continuing work, a series of polycyano-based ionic ferrocenyl compound were designed and synthesized to improve the energy level of the propellants, motivated by the general rule that nitrogen-rich energetic ionic compounds have higher standard enthalpies of formation than their nitrate analogues, arising from the introduction of nitrogen-rich groups such as tetrazolyl, azido, and/or cyano groups [23][24][25][26][27]. Herein we report eight novel binuclear ionic ferrocenyl compounds with 1,1,3,3-tetracyanopropenide (TCP) as the counter ion (Scheme 1).…”