Department of Chemistry and Institute for Sustainability and Energy at Northwestern , Northwestern University , Evanston , Illinois 60208-3113 , United States.
J Am Chem Soc. 2019 Aug 7;141(31):12236-12239. doi: 10.1021/jacs.9b06166. Epub 2019 Jul 24.
When a molecular electron donor interacts with multiple electron acceptors, quantum coherence can enhance the electron transfer (ET) rate. Here we report photodriven ET rates in a pair of donor-acceptor (D-A) compounds that link one anthracene () donor to one or two equivalent 1,4-benzoquinone () acceptors. Subpicosecond ET from the lowest excited singlet state of to two s is about 2.4 times faster than ET to one at room temperature, but about 5 times faster at cryogenic temperatures. This factor of 2 increase results from a transition from ET to one of two acceptors at room temperature to ET to a superposition state of the two acceptors with correlated system-bath fluctuations at low temperature.
当一个分子电子给体与多个电子受体相互作用时，量子相干可以提高电子转移（ET）速率。在这里，我们报告了一对给体-受体（D-A）化合物中光驱动 ET 速率，该化合物将一个蒽（）给体与一个或两个等效的 1,4-苯醌（）受体连接。从最低激发单线态到两个 s 的亚皮秒 ET 速率在室温下比 ET 到一个 快约 2.4 倍，但在低温下快约 5 倍。这种 2 的因子增加是由于室温下从 ET 到两个受体之一到低温下与相关的系统-溶剂波动的两个受体的叠加态的 ET 转变。
