Zdeněk Jalový

1,3,3-trinitroazetidine (TNAZ). Part I. Syntheses and properties

Abstract Review of more than sixteen routes for TNAZ synthesis is presented. The total yields of the most technologically attractive of thees does not exceed 30% of theory. It is stated that TNAZ is highly energetic material more powerful than RDX, which may be less vulnerable than most other nitramines, and which is suitable for applications as a castable explosive as well as a plasticizer. However, a relatively high vapour pressure, volume contraction and formation of shrinkage cavities in the solidification of its melt can be a minor disadvantage of TNAZ.

Scalable Synthesis of 1,1-Diamino-2,2-dinitroethene Without Hazardous Intermediates or by-Products

A process for the preparation of 1,1-diamino-2,2-dinitroethene suitable for scale-up was developed. The crucial features to allow scalability and enhance the process safety were the improved synthesis of 2-methoxy-2-methylimidazolidine-4,5-dione and its conversion into 2-hydroxy-2-methylimidazolidine-4,5-dione, which is a new intermediate in the synthesis of 1,1-diamino-2,2-dinitroethene. Its nitration produced 2-(dinitromethylidene)-imidazolidine-4,5-dione, whose hydrolysis into 1,1-diamino-2,2-dinitroethene was further improved. The use of trifluoroacetic acid to remove sulfuric acid prior to hydrolysis is no longer required. The described procedure yields no hazardous intermediates such as dinitromethane or 2-(dinitromethylidene)-5,5-dinitrodihydropyrimidine-4,6(1H,5H)-dione. Thus, the process safety was enhanced in comparison with the commercial production process starting from 2-methylpyrimidine-4,6-dione.

Synthesis and properties of acetamidinium salts

BackgroundAcetamidines are starting materials for synthesizing many chemical substances, such as imidazoles, pyrimidines and triazines, which are further used for biochemically active compounds as well as energetic materials. The aim of this study was to synthesise and characterise a range of acetamidinium salts in order to overcome the inconvenience connected with acetamidinium chloride, which is the only commercially available acetamidinium salt.ResultsAcetamidinium salts were synthesised and characterised by elemental analysis, mass spectrometry, NMR and - in the case of energetic salts - DTA. The structures of previously unknown acetamidinium salts were established by X-ray diffraction analysis. Hygroscopicities in 90% humidity of eight acetamidinium salts were evaluated.ConclusionsThe different values of hygroscopicity are corroborated by the structures determined by X-ray analysis. The acetamidinium salts with 2D layered structures (acetamidinium nitrate, formate, oxalate and dinitromethanide) show a lack of hygroscopicity, and the compounds with 3D type of structure (acetamidinium chloride, acetate, sulphate and perchlorate) and possessing rather large cavities are quite hygroscopic.

Gaseous Products of Dinitromethane Decomposition Determined by DTA/FTIR

Gaseous products of the thermal decomposition of dinitromethane and potassium dinitromethanide were investigated by simultaneous DTA/FTIR analyses. Both isothermal and non-isothermal DTA regimes were applied. Nitrous oxide and carbon dioxide were detected by FTIR.

The unimolecular chemistry of protonated and deprotonated 2,2-dinitroethene-1,1-diamine (FOX-7) studied by tandem mass spectrometry and computational chemistry.

2,2-Dinitroethene-1,1-diamine (FOX-7) was studied by means of electrospray ionization (ESI) and chemical ionization (CI) mass spectrometry in both positive and negative ion mode. Detailed mechanisms of unimolecular fragmentations of protonated and deprotonated FOX-7 were investigated using high- and low-energy collision-induced dissociation (CID) mass spectrometry, neutral fragment reionization mass spectrometry and quantum chemistry calculations. In deprotonated FOX-7, elimination of the carbodiimide molecule was identified as the energetically most favored fragmentation channel, closely resembling the base hydrolysis of FOX-7. The dinitromethanide ion is formed during this fragmentation as revealed by comparison with CID mass spectra of an isobaric ion prepared by the ESI of authentic sodium dinitromethanide. The proton affinity of FOX-7 was estimated as 855 kJ mol−1 by high-accuracy quantum chemistry calculations. This value corresponds to protonation at the C-2 position, though the oxygen-protonated tautomer was found to be nearly isoenergetic in the gas phase. In acetonitrile, the nitro group-protonated FOX-7 was found to be significantly less stable then its C-2 tautomer. These theoretical findings are clearly reflected in differences in fragmentations of ESI- and CI-generated [M + H]+ ions. Interestingly, the consecutive losses of OH• and NO2• radicals instead of a whole HNO3 molecule were found to account for the most abundant fragment ion in the positive ESI CID mass spectra. In the CI-generated [M + H]+ and [M+D]+ ions, substantial internal energy effects upon the CID were observed.

EXPRESS: Determination of Triacetone Triperoxide and Hexamethylene Triperoxide Diamine in Various Matrices Using Infrared Spectroscopy

The method for quantitative analysis of triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD) in different matrices is presented. The method is suitable for polymer, plastic, or cellulose matrices. It is based on dissolving, or extraction of, peroxide in the solvent and measurement in cuvettes using the Fourier transform infrared technique. These methods may be useful in analytical techniques of explosive detection and determination.