【摘要】 利用Gaussian 03程序包中的密度泛函理论在B3LYP/6-31G(d)水平下,对未掺杂、电荷掺杂和C l掺杂的聚吡咯、聚呋喃、聚噻吩进行几何全优化,并对它们的几何结构、自旋密度、自然键轨道(NBO)、前线轨道能进行了理论分析.结果表明,电荷掺杂能使聚合物键长趋于平均化,其极子分布几乎遍及了整个分子链而C l原子掺杂对聚合物的影响主要集中在与C l原子相邻的C原子上,极子分布局域在C l原子附近的大约7个碳原子上,掺杂能够明显增强π电子共轭性,降低能隙,从而增强导电性.更多还原

【Abstract】 Geometries of oligopyrrole,oligofunan,and oligothiophene(containing 6 rings) are fully optimized by using density functional theory(DFT) as implemented in GAUSSIAN 03 program.The B3LYP functional and the 6-31G(d) basis set level are employed to carry out these computations.The calculated results are analyzed from the geometry,spin density,NBO analysis,and frontier orbitals.It is found that the polarons formed by charge-dopings delocalize almost along the whole chains,while those formed by Cl-dopings localize only around the Cl atom.Dopings could significantly enhance the π-electron conjugation and reduce the band gap,which may be the reason why oligomers show conductivities only after dopings.更多还原