从二聚体到长链体系II:含二重螺轴或滑移面的体系

本文考虑了含二重螺轴或滑移面的体系由二聚体构造长链体系定性能带的方法, 讨论了一些有代表性的体系如顺式聚乙炔、扭角不为零的聚对苯撑、聚吡咯及其类似物的导电性问题, 与孤子理论进行了联系, 进一步说明从二聚体可以获得长链体系的信息。

From dimer to polymer II: Extended to systems possessing two-fold screw axis or slide plane

The approach for constructing the qual. band structure of a polymer from the corresponding dimer was extended to the system with 2-fold screw axis or glide plane. The classification of energy levels of the dimer was dependent on pseudo-symmetry/antisymmetry instead of pseudo-in-phase/out-of-phase property of the orbitals. Several elec. conductive polymers were discussed including cis-polyacetylene, poly(p-phenylene) with a twist angle, and polypyrrole and its analogs. The nature of crystal orbitals at the top and bottom of valence and conductive bands were the most important for understanding the conductive behavior of polymers. These orbitals could be considered as the extension in polymers of the frontier orbitals in mols. The conclusions based on the anal. of these orbitals about the relaxation of the backbone of the polymers after doping were consistent with those based on the concepts of soliton, polaron, dipolaron, and so on.