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对由两个相同的长直链分子(CH3(CH2)5—R(R=COOH,CH3,OH)、CH3(CH2)4—COOH))呈镜面对称分布组成的四种模型,及由两个CH3(CH2)5COOH分子平行分布组成的模型进行了量化计算,研究了分子间距、功能团、链长及排列方式对原子电荷分布及分子静电相互作用的影响.结果表明:1)分子中不同位置的亚甲基团(—CH2—)的C原子电荷各不相同.2)原子电荷不仅受到分子链长及功能团的影响,同时,当分子间距及排列方式发生改变时,原子电荷也发生改变;双分子模型较单分子模型的原子电荷变化较大.3)分子间静电作用由尾基功能团的极性决定,由强到弱为—COOH>—OH>—CH3,分子中其他原子对静电作用的贡献较小;分子链长的增加导致尾基功能团中电荷减少,从而使得分子间静电作用减弱.
Four models composed of two mirror-symmetrical distributions of the same long linear molecule (CH3 (CH2) 5-R (R = COOH, CH3, OH) and CH3 (CH2) 4-COOH) (CH3COOH) 3 (CH3 (CH2) 5COOH) were calculated and the effects of molecular spacing, functional groups, chain length and arrangement on atomic charge distribution and molecular electrostatic interaction were investigated.The results showed that: 1) The position of the methylene group (-CH2-) of the C atom charge varies .2) The atomic charge not only by the molecular chain length and functional groups at the same time, when the molecular spacing and arrangement changes, the atomic charge also occurs Changes in the molecular model than the single-molecule model of the atomic charge changes .3) The electrostatic interaction between molecules by tail functional group polarity, from strong to weak as -COOH> -OH> -CH3, the other atoms in the molecule The contribution to the electrostatic effect is smaller; the increase of the molecular chain length leads to the decrease of the charge in the tail-end functional group, which makes the electrostatic interaction between molecules weakened.