4-Amino-1H-1,2,4-triazol-1-ium nitrate

The non-centrosymmetric crystal structure of the novel semi-organic title compound, C2H5N4 +·NO3 −, is based on alternating layers of 4-amino-1H-1,2,4-triazolinium cations (formed by parallel chains of cations mediated by weak C—H⋯N hydrogen bonds) and nitrate anions inter­connected via linear and bifurcated N—H⋯O hydrogen bonds and weak C—H⋯O hydrogen bonds. N—H⋯N hydrogen bonds link the anions and cations

Spin Transition Sensors Based on β-Amino-Acid 1,2,4-Triazole Derivative

A β-aminoacid ester was successfully derivatized to yield to 4H-1,2-4-triazol-4-yl-propionate (βAlatrz) which served as a neutral bidentate ligand in the 1D coordination polymer [Fe(βAlatrz)3](CF3SO3)2·0.5H2O (1·0.5H2O). The temperature dependence of the high-spin molar fraction derived from 57Fe Mossbauer spectroscopy recorded on cooling below room temperature reveals an exceptionally abrupt single step transition between high-spin and low-spin states with a hysteresis loop of width 4 K (Tc↑ = 232 K and Tc↓ = 228 K) in agreement with magnetic susceptibility measurements. The material presents striking reversible thermochromism from white, at room temperature, to pink on quench cooling to liquid nitrogen, and acts as an alert towards temperature variations. The phase transition is of first order, as determined by differential scanning calorimetry, with transition temperatures matching the ones determined by SQUID and Mössbauer spectroscopy. The freshly prepared sample of 1·0.5H2O, dried in air, was subjected to annealing at 390 K, and the obtained white compound [Fe(βAlatrz)3](CF3SO3)2 (1) was found to exhibit a similar spin transition curve however much temperature was increased by (Tc↑ = 252 K and Tc↓ = 248 K). The removal of lattice water molecules from 1·0.5H2O is not accompanied by a change of the morphology and of the space group, and the chain character is preserved. However, an internal pressure effect stabilizing the low-spin state is evidenced

Design and Combustion Behaviour of Explosive Coordination Compounds.

Explosive coordinationcompoundsare a subject of considerableinterest becausesome of them have found specific applications, in particular, as safe primary explosives or igniters. The present work focuses on general principles of designing explosive coordination compounds. Effect of the complex molecule's constituents on explosive and physicochemical properties is considered. The main classes of organic compoundswhich might be used as ligands of explosive complexes are discussed. Since the burning rate of an explosive compound is thought to he an important characteristic determining such properties as deflagration-to-detonation transition and initiating efficiency, the work deals with studying the relationship between chemical structure and burning rate characteristics of explosive complexes. The burning rate of optimal1y designed coordination compound depends mainly on two factors: nature of oxidizers and nature of the central metal atom. Changeover from nitrate ion to perchlorate one usual1yraises the burning rate by a factor of 10 and more. Metal atom included in complexes can serve not only as a matrix, whichties up ligand-fuel and anion-oxidizer, but also as a catalyst of redox reactions occurring during combustion. It is found that each anion-oxidizer has its own set of metals that possess a catalytic activity. In the light of the experimental findings, a plausible combustion mechanism of coordination compounds has been suggested

Combustion Mechanism and Kinetics of Thermal Decomposition of Ammonium Chlorate and Nitrite

Combustion data of ammonium chlorate and nitrite have been analyzed. The leading reactions of combustion of both NH4ClO3 and NH4NO2 at low pressures have been shown to proceed in the condensed phase, with the burning rate defned by the decomposition kinetics at the surface temperature. The kinetics of NH4ClO3 and NH4NO2 decomposition have been calculated by using a condensed-phase combustion model