5-Nitro-1,2,4-triazole-3-one:A Review of Recent Advances

The 3?Nitro?1,2,4?triazole?5?one(NTO)is a high energy density materials of keen interest for both commercial and scientific worlds owing to its reduced sensitivity,better thermal stability and high performances. It plays a significant role to replace the current energetic ingredients. In this review,we summarize various strategies involved in the synthesis of NTO as well as the existing approaches to tailor its particle morphology and sizes. The most prominent properties of NTO,such as insensitivity and performance,which are usually required to produce efficient formulations,have been concisely discussed. In addition,this overview reports on some newer forms of NTO including derivatives and co?crystals available in the literature,which can enhance the NTO features and extend its applications. The advantages and shortcomings of various NTO forms for specific and potential use are also highlighted together with the attempts made to overcome these issues. Therefore,efforts will certainly continue to improve characteristics and performances of NTO either by chemical modification or by co?crystallization in order to produce promising formulations for widespread applications in the near future.

The Thermal Decomposition Mechanism and the Quantum Chemical Calculation of[Mg（H2O）6]（NTO）2·2H2O

[Mg(H2O)6](NTO)2·2H2O Was prepared by adding magnesium carbonate hydroxide to the aqueous solution of 3-nitro-1，2，4-triazol-5-one(NTO)．Its thermal decomposition mechanism was studied by DSC，TG／DTGand IR．The quantum chemical calculation on the title complex as a structure unit with the experimental geometry as atartmg values was carried out at B3LYP level with 6-31G basis set．The results show that the bonds between the coordinate waters and the Mgatom have certain extent covalent character．The net charges on nitrogen atoms of the NTO ring appear to be negative while the nitrogen atom on the nitro group(—NO2)appears to be positive which indicates—NO2 will lost first when the complex is heated to some uniform temperature and this result is in agreement with that of the thermal decomposition experiment．

The investigation of NTO/HMX-based plastic-bonded explosives and its safety performance

3-nitro-1,2,4-triazol-5-one(NTO)is the main component of insensitive munitions(IM)formulation because of its outstanding insensitive properties.In this paper,a series of NTO/HMX-based compositeexplosives were prepared and characterized.The study focuses on the effect of NTO on the perfommance of the formulations,especially the safety performance.The results revealed that the mechanical sensi-tivity of fomulations was associated with NTO content,as well as the thermal conductivity,specific heat capacity and Arrhenius parameters.Then,the high amount of NTO using in formulation was proved to be helpful for NTO/HMX-based formulation to exhibit good thermal safety.Besides,by accelerating rate calorimeter(ARC)and a modified cook-off equipment,the pressure and pressure rise rate were proved as the important indicator for judging the thermal safety performance in confined spaces.Finally,the numerical simulation was used as a credible method for predicting the respond temperature of cook-off experiment.

Designing energetic covalent organic frameworks for stabilizing high-energy compounds

As an emerging high-energy compound,3-nitro-1,2,4-triazol-5-one(NTO)is used in military explosives and rocket propellants.However,the strong acidic corrosion of NTO,and the high sensitivity and poor thermostability of its salts,severely restrict their practical applications.Therefore,a novel strategy to design and construct energetic covalent organic frameworks(COFs)is proposed in this study.We have successfully prepared a two-dimensional crystalline energetic COF(named ECOF-1)assembled from triaminoguanidine salt,in which NTO anions are trapped in the porous framework via the ionic interaction and hydrogen bonds.The results show that ECOF-1 exhibits superior thermal stability than energetic salt of NTO.It also exhibits insensitivity and excellent heat of detonation of 7,971.71 kJ·kg−1.ECOF-1 greatly inhibits the corrosiveness of NTO.In prospect,energetic COFs are promising as a functional platform to design high-energy and insensitive energetic materials.