Phenothiazinyl and carbazolyl-donor moieties can be covalently coupled to an anthraquinone acceptor unit through an Ugi four-component reaction in a rapid, highly convergent fashion and with moderate to good yields. These novel donor–acceptor dyads are electronically decoupled in the electronic ground state according to UV–vis spectroscopy and cyclic voltammetry. However, in the excited state the inherent donor luminescence is efficiently quenched. Previously performed femtosecond spectroscopic measurements account for a rapid exergonic depopulation of the excited singlet states into a charge-separated state. Calculations of the Gibbs energy of photo-induced electron transfer from readily available UV–vis spectroscopic and cyclovoltammetric data applying the Weller approximation enables a quick evaluation of these novel donor–acceptor dyads. In addition, the X-ray structure of a phenothiazinyl–anthraquinone dyad supports short donor–acceptor distances by an intramolecular π-stacking conformation, an important assumption also implied in the calculations of the Gibbs energies according to the Weller approximation.
苯并噻唑基和咔唑基供体基团可以通过Ugi四组分反应与蒽醌受体单元共价耦合,快速、高度收敛且产率中等至良好。这些新颖的供体-受体二元体在电子基态下根据紫外-可见光谱和循环伏安法电子解耦。然而,在激发态下,内在的供体发光被有效地猝灭。先前进行的飞秒光谱测量解释了激发单重态迅速放出能量进入电荷分离态。利用Weller近似法从易得的紫外-可见光谱和循环伏安法数据计算光致电子转移的吉布斯自由能,可以快速评估这些新颖的供体-受体二元体。此外,苯并噻唑-蒽醌二元体的X射线结构支持分子内π-堆积构象的短供体-受体距离,这也是Weller近似法计算吉布斯自由能的重要假设。