No abstract

Several new compounds as potential high-energy dense oxidizers (HEDOs) were synthesized from the nitro alcohols 2,2,2-trinitroethanol and 3,3,3-trinitropropanol with oxalyl chloride and hydrazide. The materials were characterized thoroughly by spectroscopic methods, and some of their crystal structures were determined through X-ray diffraction. The ener-

Compared with the well-established 2,2,2-trinitroethyl group in the chemistry of energetic materials, the 3,3,3-trinitropropyl group is less investigated regarding its chemical and energetic properties. Thus, investigations on the syntheses of several compounds containing the 3,3,3-trinitropropyl group were performed and their properties compared with the 2,2,2-trinitroethyl group. All materials were thoroughly characterized, including single-crystal X-ray diffraction studies. The thermal stabilities were examined using differential thermal analysis (DSC) and the sensitivities towards impact, friction, and electrostatic discharge were tested using a drop hammer, a friction tester, and an electrical discharge device. The energies of formation were calculated and several detonation parameters such as the velocity of detonation and the propulsion performance were estimated with the program package EXPLO5.

Sodium 5‐cyanotetrazolate sesquihydrate (1) is prepared from sodium azide and two equivalents of sodium cyanide under acidic conditions. 1 is then N‐oxidized with Oxone to sodium 5‐cyanotetrazolate monohydrate (2). Compound 2 is treated with sodium azide and a Lewis acid to form 5‐(1H‐tetrazolyl)‐2‐hydroxytetrazole monohydrate (3). Compound 3 can be deprotonated twice by various bases to give ionic derivatives such as the bis(hydroxylammonium) (4), bis(hydrazinium) (6), bis(guanidinium) (7), bis(aminoguanidinium) (8), bis(ammonium) (9), and diaminouronium (11) salt. In addition, compound 3 can only be deprotonated once, as demonstrated by the hydroxylammonium (4) and triaminoguanidinium (10) salts. Compounds 2–5 and 10–11 are structurally characterized by single‐crystal X‐ray diffraction. Additionally, compounds 2–11 are characterized by using NMR and vibrational (IR, Raman) spectroscopy as well as mass spectrometry and elemental analysis. Their thermal behaviors are studied from differential thermal analysis measurements, and the sensitivities of the compounds toward shock, friction, and electrostatic discharge are determined. In addition, the heats of formation are calculated (atomization method, CBS‐4M enthalpies), and several detonation/propulsion parameters are computed with the EXPLO5 code.

The thra¢-membered ring of aziridine-2-carboxylic acid, which is susceptible to alining by nuclcophilcs, has been analyzed as a potential useful handle for the desisn of ~p¢cifi¢ irrevcrsibl~ inhibitors of ¢ysteine proteinases. For this thiol-reactiv¢ amino avid, an imino analogue of proline, a s~ond.order rate constant of 17.07 M-~.s -~ for inactivation of papain was determined. Thus° the aziridine moiety proved to be remarkably more reactive than activated double bonds° ¢.g. N-eth~,lmaleimide, or halides such as,,-iodopropionic acid or chloroaoctie acid. Since it dccs not alkylate histidine under conditions in which quantitative alkylation occurs with N-ethyl-maleimide, it could represent an interesting reactive amino acid unit for the synthesis of a new class oi" irreversible inhibitors, at least in terms of specificity of the chemical reaction involved in the inactivation process.