2- (two nitro Ya Jiaji) -4, 5- (Er Qiangji) imidazolidine (DDNI) study on the synthesis and structure properties of the derivative

1,1-Diamino-2,2-Dinitroethylene(FOX-7) is a novel high-energy material with high thermal stability and low sensitivity in future.2-(Dinitromethylene)imidazolidine-4,5-diol(DDNI), one electrophilic derivatives of FOX-7, is the new high energetic materials. So it is very important to study the synthesis and the properties of DDNI for futher theoretical research and practical application.Targeted at exploiting the superior performance of DDNI and searching for more ideal novel energetic materials, based on the original foundation, we react DDNI with various nitrogen-containing nucleophiles and some alcohols, respectively. Six derivatives of DDNI were synthesized and three kinds of single crystal were firstly obtained. Meanwhile, the structure of their single crystals were determined by Area detector X-ray diffractometer. The three new compounds are DMDNI、DEDNI and DADNI.Gaussian-03w package was used to optimize structure geometry and compute frequencies of the compounds. The optimized parameters, natural atomic charges, frontier orbital energy and main atomic orbital percentage were provided, which can be very profound and important informations for theoretical analysis.The thermal behaviors of the above five compounds were studied under non-isothermal conditions by DSC and TG/DTG methods. The Kissinger method, Ozawa method and integral method were employed to determine kinetic parameters and thermal decomposition mechanism functions of DBDNI, DCDNI, DMDNI and DADNI in exothermic processes:The entropy of activation (ΔS≠), enthalpy of activation (ΔH≠), Gibbs free energy of activation (ΔG≠) and critical temperature of thermal explosion (Tb) as well as thermal ignition temperature TTIT of the five compounds were obtained.The continuous specific heat capacity of above compounds were determined. Based on the Cp results, the thermodynamic values (enthalpy, entropy and Gibbs free energy) of compounds between283-353K, relative to the standard temperature298.15K, were derived through thermodynamic equations. Meanwhile, using Cp functions and thermal decomposition parameters, the adiabatic time-to-explosion of DBDNI、DMDNI and DADNI were estimated, as an important parameter, which can be used to estimate thermal stability and safety of engetic materials directly.