Coordination Study Of Strontium Salt Coordinate With Organic Ligands Containing Nitrogen

First,the coordination molecules of strontium nitrate and 2,4-double nitro imidazole（2,4-DNI）were studied,the ligand models were constructed in aqueous solution environment,by using the density functional theory method in Gaussian09software,to design molecular modle and calculate the coordinated model theoretically,the aim was to comprehensively utilize the oxidation of strontium salts and high energy density of imidazole,geometrical optimization and the theoretical detonation parameters of coordinated molecular results are as follows:By analyzing and comparing the stability and geometrical optimization structure of the 4 coordinated molecules,it was concluded that the most stable molecular model of strontium nitrate and 2,4-double nitro imidazole was“butterfly”structure,and the molecular formula was[Sr（2,4-DNI）₂（H₂O）₄]²⁺·2NO₃^-;The absorption peaks of the wave numbers of 3344.46cm^-1 and 1254.82cm^-1 in the infrared spectrum correspond to the telescopic vibration and the in-plane deformation vibration of-OH,indicating that the water molecules were involved in the coordination of the coordination;The existence of two moderately strong absorption peaks at 709.677cm^-1 and 765.73cm^-1proved the existence of Sr-O and Sr-N,indicating that the complexes were coordinated by central ions,water molecules and 2,4-double nitro imidazole molecules.The experimental and theoretical calculations of the bond length between center ions and N and O had no more than 3.48%error.The error between bond angle experiment and theoretical calculation was not more than 1.98%.The above parameters and conclusions can confirm that the best coordination molecule was[Sr（2,4-DNI）₂（H₂O）₄]²⁺·2NO₃^-.Based on the theoretical calculation of the detonation parameters of the best coordinated molecule,it was known that the molar volume of the coordination molecule is 248.779cm³/mol,the molar mass is 541.838g/mol,and the density is d=2.18g/cm³.According to the Kamlet-Jacobs empirical formula,the theoretical and theoretical detonation velocities and theoretical detonation pressures were D=9.42km/s,p=43.82GPa.Compared with the parameters of common explosives,the complexes meets the requirements of high density explosives.During the process of above study,comparison of stability analysis results of various molecular models found that the stability of split valence basis sets the optimized geometric structure was higher than that of the pseudopotential basis set,the characterization of the best coordination also confirmed this result,which showed that the chosen method and the base group were reasonable.On this basis,the results of the coordination of strontium nitrate and 4-nitroimidazole were as follows:By analyzing and comparing the stability and geometry optimization of 4 kinds of coordination molecules,the best coordinated model was"chair"structure,and the molecular formula was[Sr（4-NI）_2（）NO32].By the data representation and analysis table of bond lengths,central ion and N and O binding sites of the bond length were in the range of 2.64021-2.74710?,bond length between symmetrical ligands were extremely close,two relative ligand bond angles were 179.987o,179.424o,179.411o,very close to180o,so the ligand（3）with 6 coordinated and"chair"was relatively stable,symmetry good.The detonation parameters of the coordinated molecule were calculated:the molecular formula of the complex is C₁₂H₁₂N₁₄O₁₄Sr,its molar volume is364.753cm³/mol,the molar mass is 663.993g,and the density is d=1.820g/cm³.According to the Kamlet-Jacobs empirical formula,the theoretical detonation velocity and theoretical detonation pressure are D=7.93km/s,p=27.97GPa.It is worth further research and utilization.