Roy Palas, Bressan Giovanni, Gretton Jacob, Cammidge Andrew N, Meech Stephen R
School of Chemistry, University of East Anglia, Nowich, NR4 7TJ, UK.
Department of Life Sciences, Imperial College London, London, SW7 2BX, UK.
Angew Chem Int Ed Engl. 2021 May 3;60(19):10568-10572. doi: 10.1002/anie.202101572. Epub 2021 Mar 30.
Knowledge of the factors controlling excited state dynamics in excitonically coupled dimers and higher aggregates is critical for understanding natural and artificial solar energy conversion. In this work, we report ultrafast solvent polarity dependent excited state dynamics of the structurally well-defined subphthalocyanine dimer, μ-OSubPc . Stationary electronic spectra demonstrate strong exciton coupling in μ-OSubPc . Femtosecond transient absorption measurements reveal ultrafast excimer formation from the initially excited exciton, mediated by intramolecular structural evolution. In polar solvents the excimer state decays directly through symmetry breaking charge transfer to form a charge separated state. Charge separation occurs under control of solvent orientational relaxation.
了解激子耦合二聚体和更高聚集体中控制激发态动力学的因素对于理解天然和人工太阳能转换至关重要。在这项工作中，我们报道了结构明确的亚酞菁二聚体μ-OSubPc超快溶剂极性依赖的激发态动力学。稳态电子光谱表明μ-OSubPc中存在强激子耦合。飞秒瞬态吸收测量揭示了由分子内结构演化介导的从初始激发激子超快形成激基缔合物。在极性溶剂中，激基缔合物态通过对称性破缺电荷转移直接衰减形成电荷分离态。电荷分离在溶剂取向弛豫的控制下发生。
