1,1‐Diamino‐2,2‐dinitroethylenes are always zwitterions

Abstract

The nitration of tetraiodoethylene (7) yields 1,1-diiodo-2,2-dinitroethylene (8). The latter reacts with alkylamines 9 or alkyldiamines 11 to give the corresponding acyclic 1,1-diamino-2,2-dinitroethylenes 10 or their cyclic analogs 12, respectively. On the basis of liquid and solid-state (13)C and (15)N NMR data, x-ray analysis and ab initio calculations, we suggest that the title compounds are always zwitterionic and that the C(A)-C(N) bond is not a true double bond.

Application of [PVI-SO3H]NO3 as a novel polymeric nitrating agent with ionic tags in preparation of high-energetic materials

“…10,11 Architecture of novel renewable and sustainable nitrating reagent in the organic transformation has attracted much attention in the science and industry because of their unique properties, such as efficiency, reusability, reactivity, stability, selectivity, generality and easy separation of the catalyst. [12][13][14][15][16][17][18] These methods of preparation of energetic materials were previously reported in the presence of some various nitrating agents, co-catalysts, and solvents, mixed acid of concentrated nitric acid and sulfuric acid, high temperature, long reaction times, and low yields [19][20][21][22][23][24][25][26][27][28][29][30] (Scheme 1).…”

Insensitive High Explosives: III. Nitroguanidine – Synthesis – Structure – Spectroscopy – Sensitiveness

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 A crystallographic and theoretical analysis of a series of 1,1-diamino-2,2-dinitroethylenes shows a similar situation to persist. The most important member of this the group, the insensitive high explosive FOX-7 (3) is also best represented by a zwitterionic structure of the type indicated right in Figure 24 with shorter than normal d(CÀNH) bonds, 132 pm [110].…”

Twisted C=C Double Bonds with Very Low Rotational Barriers in Dioxanediones and Isoxazolones Determined by Low‐Temperature Dynamic NMR Spectroscopy and Computational Chemistry

“…Substitution of C=C double bonds with electron‐donating and electron‐withdrawing substituents at opposite termini (push‐pull olefins) leads to polarization and lengthening of those bonds (Scheme ), twisting about the double bonds, and reduced barriers to rotation With highly polarized double bonds, twisting angles up to 90° can be achieved , . As the ground‐state twisting angle increases, the calculated barrier to rotation usually decreases, and barriers of only a few kcal/mol can result, contrasting the habitual 65 kcal/mol rotational barrier in ethylene.…”