Institute of Chemical Research of Catalonia , Avgda. Països Catalans 16, 43007 Tarragona, Spain.
J Am Chem Soc. 2014 Aug 13;136(32):11436-43. doi: 10.1021/ja5052236. Epub 2014 Aug 4.
Herein, we report the synthesis of guanidinium bis-porphyrin tweezers 1 and fullerene carboxylate 3, their assembly into a novel supramolecular 1@3 electron donor-acceptor hybrid, and its characterization. In solution, the binding constant affording 1@3 is exceptionally high. 1@3, which features a highly confined topography, builds up from a combination of guanidinium-carboxylate hydrogen bonding and π-π stacking/charge-transfer motifs. The latter is governed by interactions between the electron-donating porphyrin and the electron-accepting fullerene. Importantly, positive cooperativity between the applied binding motifs is corroborated by a number of experimental techniques, such as NMR, absorption, fluorescence, etc. In addition, transient absorption experiments shed light onto electron-transfer processes taking place in the ground state and upon photoexcitation. In fact, porphyrin excitation powers an electron transfer to the fullerene yielding charge separated state lifetimes in the nanosecond regime.
本文报道了胍基双卟啉镊子 1 和富勒烯羧酸酯 3 的合成，以及它们组装成新型超分子 1@3 给体-受体杂化物及其表征。在溶液中，形成 1@3 的结合常数非常高。1@3 具有高度受限的拓扑结构，由胍基-羧酸氢键和π-π堆积/电荷转移模式组合而成。后一种模式受供电子卟啉和受电子富勒烯之间相互作用的控制。重要的是，通过 NMR、吸收、荧光等多种实验技术证实了应用的结合模式之间存在正协同作用。此外，瞬态吸收实验揭示了在基态和光激发下发生的电子转移过程。事实上，卟啉激发将电子转移给富勒烯，产生纳秒级的电荷分离态寿命。
