HMX与含硼化合物相互作用的理论计算

Theoretical calculation of interaction between HMX and B-containing compound

在PBX体系中加入合适的键合剂通常能改善HMX与高聚物的界面作用.为了预测其界面作用强度及粘合效果,本文采用B3LYP密度泛函方法和6-31G*基组计算HMX与含硼化合物BR1R2R3的相互作用.优化得到了存在B…O相互作用的HMX…BR1R2R3复合物的几何构型.计算结果表明,HMX…BH3和HMX…BH2(CH3)中的B与O原子间相互作用强,二者分子间相互作用能在MP2/6-31++G**//B3LYP/6-31G*水平上分别为-65.3 kJ/mol和-40.2 kJ/mol.由于空间位阻效应HMX中的O原子与BH(CH3)2、B(CH3)3和B(OH)(CH3)(CH2NH2)中的B原子距离大于3.理论计算结果与实验结果基本一致.

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 HM …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 HM and the B atom in compounds BH（CH3）2, B （CH3）3, and B（OH） （CH3） （CH2NH2） is larger than 3 A because of stereo- hindrance effect. The calculated results are in agreement with the experiment.