瑞典乌普萨拉大学Leif Hammarstrm团队报道了分子三联体中的质子耦合能量转移。相关研究成果发表在2022年7月21日出版的国际学术期刊《科学》。

实验发现了一种光化学机制，表示为质子耦合能量转移（PCEnT）。在约400 nm的光激发后，一系列蒽-苯酚-吡啶三元化合物形成局部激发蒽态，导致苯酚-吡啶单元产生约550 nm荧光。苯酚吡啶的直接激发需要330 nm左右的光，但苯酚吡啶单元内的耦合质子转移降低了其激发态能量，因此可以接受蒽的激发能。

因此，尽管蒽荧光和苯酚-吡啶吸收之间缺乏光谱重叠，但仍发生单线态-单线态能量转移。此外，理论计算表明，蒽和苯酚吡啶单元之间的电荷转移可以忽略不计。

PCEnT被认为是一种可能与生物系统和未来光子器件相关的基本反应。

附：英文原文

Title: Proton-coupled energy transfer in molecular triads

Author: Belinda Pettersson Rimgard, Zhen Tao, Giovanny A. Parada, Laura F. Cotter, Sharon Hammes-Schiffer, James M. Mayer, Leif Hammarstrm

Issue&Volume: 2022-07-21

Abstract: A photochemical mechanism was experimentally discovered and denoted proton-coupled energy transfer (PCEnT). A series of anthracene-phenol-pyridine triads formed the local excited anthracene state after light excitation at ca. 400 nm, which led to uorescence around 550 nm from the phenol-pyridine unit. Direct excitation of phenol-pyridine would have required light around 330 nm, but the coupled proton transfer within the phenol-pyridine unit lowered its excited state energy so that it could accept excitation energy from anthracene. Singlet-singlet energy transfer thus occurred despite the lack of spectral overlap between the anthracene uorescence and the phenol-pyridine absorption. Moreover, theoretical calculations indicated negligible charge transfer between the anthracene and phenol-pyridine units. PCEnT was suggested as an elementary reaction of possible relevance to biological systems and future photonic devices.

DOI: abq5173

Source: https://www.science.org/doi/10.1126/science.abq5173