Hefei National Laboratory for Physical Science at Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, PR China.
Phys Chem Chem Phys. 2010 Oct 28;12(40):13070-5. doi: 10.1039/c003944f. Epub 2010 Sep 2.
Recently we characterized the low-lying electronic excitations of H-aggregated perylene bisimide (PBI) dyes using the time-dependent long-range-corrected density functional theory (TD-LRC-DFT) and the mixed intramolecular Frenkel exciton (FE) and the intermolecular charge-transfer exciton (CTE) model (F. Pan, F. Gao, W. Z. Liang and Y. Zhao, J. Phys. Chem. B, 2009, 113, 14581.). We found that the dimer absorption follows closely the spectra of PBI aggregates in solution, and demonstrates strong mixing of two kinds of excitons. Here we implement the theoretical approaches to study the electronic excitations of a family of bridged naphthalene dimers. It is found that TD-LRC-DFT reproduces all experimentally observed trends in the absorption profiles. By comparing the results obtained from the popular hybrid exchange-correlation functionals with these from LRC-DFT, we display how the experimentally measured dipole-allowed mixed exciton states of systems are formed. The major terms which contribute to the experimentally measured dimeric splitting are qualitatively identified. Three-dimensional plots of transition charge density help visualize how the excitons couple.
最近，我们使用时间相关的长程修正密度泛函理论（TD-LRC-DFT）和混合分子内弗伦克尔激子（FE）和分子间电荷转移激子（CTE）模型（F. Pan，F. Gao，W. Z. Liang 和 Y. Zhao，J. Phys. Chem. B，2009，113，14581.）来描述聚集态的苝二酰亚胺（PBI）染料的低能电子激发。我们发现二聚体吸收与溶液中 PBI 聚集体的光谱非常吻合，并表现出两种激子的强烈混合。在这里，我们实施了理论方法来研究一系列桥连萘二聚体的电子激发。结果发现，TD-LRC-DFT 再现了吸收曲线中所有实验观察到的趋势。通过比较来自流行的混合交换相关泛函与 LRC-DFT 的结果，我们展示了如何形成系统中实验测量的偶极允许混合激子态。定性识别了对实验测量的二聚体分裂有贡献的主要项。跃迁电荷密度的三维图有助于可视化激子的耦合方式。
