Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, Jakob Welder-Weg 11, 55099 Mainz, Germany.
J Phys Chem A. 2010 Feb 4;114(4):1639-49. doi: 10.1021/jp910551u.
The singlet and triplet electronic excitation manifold of 3.3biphenylophane (BPP), an intramolecular dimer, and 4,4'-dimethylbiphenyl (DMBP), the corresponding monomer, has been analyzed by employing the approximate coupled-cluster singles and doubles model (CC2). The calculated triplet-triplet and singlet-singlet transient absorption spectra show good agreement with recent experimental results. The calculations suggest a strong interaction of the two biphenyl moieties of BPP in the first singlet and triplet excited states due to the overlapping pi-electron systems, and Forster-Dexter theory for weak coupling cannot be applied. Both the first excited singlet and triplet states of BPP can be characterized as excimeric states with a strong admixture of charge-transfer contributions.
3.3联苯并菲（BPP）是一种分子内二聚体，4,4'-二甲基联苯（DMBP）是其对应的单体，其单重态和三重态电子激发能级结构已采用近似耦合簇单双激发模型（CC2）进行了分析。计算得到的三重态-三重态和单重态-单重态瞬态吸收光谱与最近的实验结果吻合较好。计算表明，由于重叠的π电子体系，BPP 的两个联苯部分在第一单重态和三重态激发态之间存在很强的相互作用，因此不能应用福斯特-德克斯特理论进行弱耦合计算。BPP 的第一激发单重态和三重态都可以被描述为具有强烈电荷转移贡献的激基复合物态。
