Preparation, Crystal Structure and Thermal Behavior of K( FOX-7)•H2O

A high-energy organic potassium salt of 1,1-diamino-2,2-dinitroethlyene( FOX-7) was synthesized by mixing FOX-7 and KOH in water-methanol system. Crystal structure of K( FOX-7)center dot H2O was determined by X-ray diffraction analysis. The crystal belongs to triclinic crystallographic system, space group PI and cell parameters: a = 0. 7493 ( 2) urn, b = 0. 9767 ( 3) urn, c = 2. 0035 ( 5) nm, alpha = 90. 017 ( 4)degrees, beta = 97. 129 (4)degrees, gamma = 90. 019 (4)degrees, v = 1.4548 ( 7) nm(3), D-c =1.865 g/cm(3), mu = 0. 724 mm(-1), F(000) = 832, Z = 8, R-1 = 0.0523, wR(2) = 0.1082. The thermal behavior of K( FOX-7) center dot H2O was studied, and the apparent activation energy and pre-exponential factor of the second decomposition reaction are 135. 9 kJ/mol and 10(12, 17) s(-1), respectively. The critical temperature of thermal explosion is 212. 02 degrees C. The specific heat capacity of K( FOX-7) center dot H2O was determined with micro-DSC method, and the molar heat capacity is 210.88 J.mol(-1). K-1 at 298. 15 K. Thermodynamic functions of K( FOX-7)center dot H2O, relative to the standard temperature 298. 15K, were calculated through thermodynamic relationship, and the adiabatic time-to-explosion also was obtained as a certain value between 15. 7-16. 8 s.