Fratiloiu Silvia, Grozema Ferdinand C, Siebbeles Laurens D A
Department of Radiation Chemistry, Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands.
J Phys Chem B. 2005 Mar 31;109(12):5644-52. doi: 10.1021/jp0443310.
A quantum chemical study of the electronic structure of negatively charged phenylenevinylene (PV) oligomers and methoxy-substituted derivatives is presented. The geometries of the PV oligomers were optimized using density functional theory. The geometry deformations are found to be delocalized along the entire oligomer chain without indication of polaron formation. The optical absorption spectra of the negatively charged PVs were calculated using both time-dependent density functional theory (TDDFT) and the singly excited configuration interaction method with an intermediate neglect of differential overlap reference wave function (INDO/s-CIS). The available experimental optical absorption energies are reproduced by the calculations. Introduction of methoxy substituents reduces the transition energies, while this does not have a strong effect on the charge distribution along the chain. DFT calculations yield a more delocalized excess negative charge than that of INDO/s-CIS calculations.
本文介绍了对带负电荷的亚苯基亚乙烯基（PV）低聚物及其甲氧基取代衍生物的电子结构进行的量子化学研究。使用密度泛函理论对PV低聚物的几何结构进行了优化。发现几何结构变形沿整个低聚物链呈离域状态，没有极化子形成的迹象。使用含时密度泛函理论（TDDFT）和单激发组态相互作用方法（中间忽略微分重叠参考波函数，即INDO/s-CIS）计算了带负电荷的PV的光吸收光谱。计算结果再现了现有的实验光吸收能量。甲氧基取代基的引入降低了跃迁能量，而这对沿链的电荷分布没有强烈影响。与INDO/s-CIS计算相比，密度泛函理论（DFT）计算得出的过量负电荷离域程度更高。
