【摘要】 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。更多还原

【Abstract】 The molecular structure of EDA-cored 1.0G polyamidoamine(PAMAM) was fully geometrical optimized using the density functional theory(DFT) B3LYP method,as well as Hartree-Fock method at both 3-21G and 6-31G~* level.The results obtained at various levels were discussed and compared with each other and with the available experimental datas.It was shown that the calculations performed at B3LYP/6-31G~* level could produce more reliable results.The results derived at B3LYP/6-31G~* level were studied.The steady conformation was not entirely symmetrical,and the four branches were basically on the same plane.The primary amine,tertiary and secondary amine brought about by the decreasing number of negative charge,and the highest occupied molecular orbital concentrated on the nuclear.更多还原