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1,2,4‐Triazolium‐Cation‐Based Energetic Salts
Author(s) -
Darwich Chaza,
Klapötke Thomas M.,
Sabaté Carles Miró
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200800340
Subject(s) - chemistry , iodide , perchlorate , melting point , thermal decomposition , detonation , inorganic chemistry , salt metathesis reaction , metathesis , organic chemistry , ion , polymerization , explosive material , polymer
3,4,5‐Triamino‐1,2,4‐triazole (guanazine, 1 ) can be readily methylated with methyl iodide yielding methylguanazinium iodide ( 2 ). Salts containing the novel methylguanazinium cation with energetic anions were synthesised by metathesis reactions with silver azide ( 3 ), silver nitrate ( 4 ), silver perchlorate ( 5 ), sodium 5,5′‐azotetrazolate ( 6 ), silver 5‐nitrotetrazolate ( 7 ) and silver dinitramide ( 8 ), yielding a new family of heterocycle‐based salts, which were fully characterised by analytical (mass spectrometry and elemental analysis) and spectroscopic methods (IR, Raman and NMR). In addition, the molecular structures of all compounds were confirmed by X‐ray analysis, revealing extensive hydrogen‐bonding in the solid state and densities between 1.399 ( 3 ) and 1.669 g cm −3 ( 5 ). The hydrogen‐bonded ring motifs are discussed in the formalism of graph‐set analysis for hydrogen‐bond patterns and compared to each other. Preliminary sensitivity testing of the crystalline compounds indicate surprisingly low sensitivities to both friction and impact, the highest friction and shock sensitivity being found for the perchlorate ( 5 , 220 N) and the dinitramide ( 8 , 20 J) salts, respectively. In addition, DSC analysis was used to assess the thermal stabilities of the compounds: 3 – 6 melt above 200 °C with concomitant decomposition, whereas 7 and 8 have clearly defined melting points at 162 and 129 °C, respectively, and with decomposition occurring about 30 °C above the melting point. Lastly all compounds have positive calculated heats of formation between 336 ( 4 ) and 4070 kJ kg −1 ( 6 ) and calculated detonation velocities in the range between 8330 ( 7 ) and 8922 m s −1 ( 6 ) making them of interest as new highly energetic materials with low sensitivity.