Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.2.42 (DTA)
 1,693 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The reaction of SiCl4 with an excess of (PPN)N3 (PPN+ = [(Ph3P)2N]+) affords selectively (PPN)2[Si(N3)6] (1). Simultaneous thermal analysis (TG-DTA) shows that the hexaazidosilicate salt is remarkably stable, melting at Tonex = 214 degrees C. Melting of 1 is followed by two distinct exothermic decomposition processes at Ton = 256 and 321 degrees C, the first one involving elimination of N2 and the second one degradation of the PPN cations and evolution of Si(N3)4, N2, and some HN3. The crystal structure of 1 consists of discrete PPN+ cations and S2 symmetric [Si(N3)6]2- anions, which have a very rare, octahedral SiN6 framework and the highest nitrogen content (90%) among the hexaazidometallates reported so far. The IR, Raman, 29Si, and 14N NMR spectra of 1 in CH3CN suggest in combination with the calculated spectra the presence of intact [Si(N3)6]2--anions of S6 symmetry in solution. Geometry optimizations with various methods and basis sets show an S6 symmetric structure to be the most stable [Si(N3)6]2- isomer, the calculated bonding parameters comparing well with the experimental values.
 ...
PMID:The hexaazidosilicate(IV) ion: synthesis, properties, and molecular structure. 1238 Nov 65

A convenient access to 5-(trinitromethyl)-2H-tetrazole (HTNTz) has been developed, based on the exhaustive nitration of 1H-tetrazole-5-acetic acid, which was prepared from ethyl cyanoacetate and HN3 in a 1,3-dipolar cycloaddition reaction, followed by basic hydrolysis. HTNTz was converted into the ammonium, guanidinium, rubidium, cesium, copper, and silver 5-(trinitromethyl)-2H-tetrazolates. In addition, the ammonia adducts of the copper and silver salts were isolated. The reaction of HTNTz with hydrazine and hydroxylamine resulted in the formation of hydrazinium 5-(dinitromethyl)tetrazolate and hydroxylammonium 5-(dinitromethyl)-1H-tetrazolate, respectively. Acid treatment of both 5-(dinitromethyl)tetrazolates resulted in the isolation of 5-(dinitromethylene)-4,5-dihydro-1H-tetrazole, which was converted into potassium 5-(dinitromethyl)-1H-tetrazolate by reaction with K2CO3. All prepared compounds were fully characterized by (1)H, (13)C, (14)N, and (15)N NMR spectroscopy and X-ray crystal structure determination. Initial safety testing (impact, friction, and electrostatic sensitivity) and thermal stability measurements (differential thermal analysis, DTA) were also carried out. The 5-(trinitromethyl) and 5-(dinitromethyl)tetrazoles are highly energetic materials that explode upon impact or heating.
 ...
PMID:Energetic high-nitrogen compounds: 5-(trinitromethyl)-2H-tetrazole and -tetrazolates, preparation, characterization, and conversion into 5-(dinitromethyl)tetrazoles. 2372 11

5-(Fluorodinitromethyl)-2H-tetrazole (HFDNTz) has been prepared by the cycloaddition reaction of HN3 with F(NO2)2CCN, which in turn was prepared by aqueous fluorination of sodium dinitrocyanomethanide. HFDNTz was converted into the ammonium, silver and tetraphenylphosphonium 5-(fluorodinitromethyl)tetrazolates. While the reaction of trinitroacetonitrile with HBr, followed by the treatment with NaOH, resulted in the formation of sodium dinitrocyanomethanide, the reaction of trinitroacetonitrile with aqueous ammonia produced ammonium dinitrocyanomethanide. Hydrazinium dinitromethanide was obtained from trinitroacetonitrile and hydrazine hydrate. All compounds were fully characterized by multinuclear NMR spectroscopy, IR spectroscopy and X-ray crystal structure determinations. Initial safety testing (impact and friction sensitivity) and thermal stability measurements (DTA) were also carried out.
...
PMID:5-(Fluorodinitromethyl)-2H-tetrazole and its tetrazolates -- preparation and characterization of new high energy compounds. 2582 67