Theoretical calculation of interaction between HMX and B-containing compound

The introduction of proper bonding agents into polymer bonded explosives can usually improve the surface interaction between HMX and polymer. To predict the interfacial interaction strength and the bonding effect, in this paper the B3LYP density functional method and the 6-31G basis set have been employed to study the interaction between HMX and B-containing compound BR1R2R3. The optimized geometries of HMX ...BR1R2R3 in which the B...O interaction exists have been obtained. Calculated results show that the B...O interaction is very strong in both HMX...BH3 and HMX...BH2(CH3) complexes. The MP2/6-31 ++ G**// B3LYP/6-31G* calculated intermolecular interaction energies for the two complexes are -65.3 kJ/mol and -40.2 kJ/mol, respectively. Compounds BH2R have been predicted to be efficient bonding agents. It is worth mentioning that the distance between the O atom of HMX and the B atom in compounds BH(CH3)2, B (CH3)3, and B(OH)(CH3)(CH2NH2) is larger than 3 Angstrom because of stereo-hindrance effect. The calculated results are in agreement with the experiment. (authors)