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采用传统的Hartree-Fock(HF)从头算和密度泛函B3LYP方法,选择不同的基组水平(3-21G,6-31G~*)对以乙二胺为核的1.0代PAMAM分子进行全几何优化,并对结果进行比较,同时与实验值进行对照。结果表明,B3LYP/6- 31G~*方法得到的结果更可靠。B3LYP/6-31G~*计算结果表明,1.0代PAMAM分子构象不完全对称,4个支链基本在一个平面上,伯胺,仲胺和叔胺上的N原子所带负电荷数逐渐减少,HOMO轨道主要集中在核上,核极易发挥供电子作用。
The traditional Hartree-Fock (HF) ab initio and density functional B3LYP method was used to select the different basis sets (3-21G, 6-31G ~ *) for the first generation PAMAM with ethylenediamine as the core. Optimization, and the results were compared with the experimental value at the same time. The results show that B3LYP / 6-31G ~ * method is more reliable. The calculated results of B3LYP / 6-31G ~ * show that the molecular configuration of 1.0 generation PAMAM is not completely symmetrical and the four branches are basically in one plane. The number of negative charges carried by N atoms on primary amine, secondary amine and tertiary amine decreases gradually, HOMO orbit is mainly concentrated in the nucleus, the nucleus can easily play an electron role.