论文部分内容阅读
采用密度泛函B3LYP方法,在6-311++G(2d,p)水平上对外电场中的R-NO_2(R=-CH_3、-NH2、-OCH3)及其HF氢键体系(R-NO2…HF)进行了结构优化,然后在6-311++G(2d,p)和aug-cc-p VTZ基组水平上分别用B3LYP和MP2(full)方法进行了能量计算,并对单体R-NO_2在CCSD(T)方法下进行了更为详细的考量,最后借助分子中的原子(AIM)理论以及分子静电势揭示了结构和能量变化的本质.结果表明,在一定方向和大小的外电场作用下,单体分子的相对总能量降低,引发键键长变短,偶极矩增大,引发键离解能变大;氢键复合物比其单体引发键键长更短,引发键键能也更大.
The R-NO 2 (R = -CH 3, -NH 2, -OCH 3) and its HF hydrogen bond system (R-NO 2) in the external electric field were measured by density functional theory B3LYP at 6-311 ++ G (2d, ... HF), and then the energy calculations were performed on the 6-311 ++ G (2d, p) and aug-cc-p VTZ basis sets using the B3LYP and MP2 (full) Under the CCSD (T) method, R-NO_2 is considered in more detail. Finally, the nature of the structure and energy changes are revealed by means of atomic AIM theory and molecular electrostatic potential. The results show that in a certain direction and size Under the action of the external electric field, the relative total energy of monomer molecules decreases, the bond bond length becomes shorter and the dipole moment increases, and the dissociation energy of the initiating bond can be larger; the hydrogen bond complex has a shorter bond length than the monomer bond, Keys can be bigger.