聚丙烯腈PAN结构链的密度泛函理论研究

Density Functional Theory Study on the Polyacrylonitrile Chains

在HF/STO-3g基础上,利用密度泛函B3P86方法,选用6-311g基组,对聚丙烯腈PAN的结构链进行了理论研究.在结构优化方面,主链CC平均键长0.154 1 nm,属于sp3型杂化.支链CC平均键长0.146 0 nm.CN平均键长0.115 7 nm.电荷分布方面,计算得出,主链C原子带较强的负电荷,N原子带负电荷,相对较弱.H原子带较强的正电荷,是和N原子相连的C原子所带正电荷的3倍多.最后分析了结构链的振动模式.

Based on Hartree-Fock self-consistent method, the equilibrium geometries of the polyaerylonitrile （PAN） chains have been theoretically studied using the B3P86 method at the 6-311g levels. As for the optimized structures, the present work has obtained the result that the average distance of the C atom couple in main chain is 0. 154 1 nm, and the bond belongs to sp3 hybrid; the average distance of the C atom couple in branch chain is 0. 146 0 nm; the average distance of C atom bonding with N atom is 0. 115 7 nm. For the charge distribution, the C atom in main chain has comparatively more negative charge, while that belonging to N atom is fewer; the positive charge belonging to H atom is more than three times as that belonging to the C atom bonding with N atom. Finally, the vibration models of the chains have been analyzed.