气候变化领域集成服务门户(CCPortal): Molecular excitonic seesaws

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DOI	10.1073/pnas.1722229115
	Molecular excitonic seesaws
	Wilhelm P.; Schedlbauer J.; Hinderer F.; Hennen D.; Höger S.; Vogelsang J.; Lupton J.M.
发表日期	2018
ISSN	0027-8424
起始页码	E3626
结束页码	E3634
卷号	115 期号:16
英文摘要	The breaking of molecular symmetry through photoexcitation is a ubiquitous but rather elusive process, which, for example, controls the microscopic efficiency of light harvesting in molecular aggregates. A molecular excitation within a π-conjugated segment will self-localize due to strong coupling to molecular vibrations, locally changing bond alternation in a process which is fundamentally nondeterministic. Probing such symmetry breaking usually relies on polarization-resolved fluorescence, which is most powerful on the level of single molecules. Here, we explore symmetry breaking by designing a large, asymmetric acceptor-donor-acceptor (A1-DA2) complex 10 nm in length, where excitation energy can flow from the donor, a π-conjugated oligomer, to either one of the two boron-dipyrromethene (bodipy) dye acceptors of different color. Fluorescence correlation spectroscopy (FCS) reveals a nondeterministic switching between the energy-transfer pathways from the oligomer to the two acceptor groups on the submillisecond timescale. We conclude that excitation energy transfer, and light harvesting in general, are fundamentally nondeterministic processes, which can be strongly perturbed by external stimuli. A simple demonstration of the relation between exciton localization within the extended π-system and energy transfer to the endcap is given by considering the selectivity of endcap emission through the polarization of the excitation light in triads with bent oligomer backbones. Bending leads to increased localization so that the molecule acquires bichromophoric characteristics in terms of its fluorescence photon statistics. © 2018 National Academy of Sciences. All rights reserved.
英文关键词	Bodipys; Excited-state molecular dynamics; Excitonics; Light harvesting; Single-molecule spectroscopy
语种	英语
scopus关键词	oligomer; Article; chemical structure; conjugation; controlled study; energy transfer; field emission; fluorescence correlation spectroscopy; fluorescence polarization; light absorption; light harvesting system; light scattering; molecular dynamics; photon correlation spectroscopy; priority journal; synthesis
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160554
作者单位	Wilhelm, P., Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Regensburg, 93053, Germany; Schedlbauer, J., Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Regensburg, 93053, Germany; Hinderer, F., Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, 53121, Germany; Hennen, D., Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, 53121, Germany; Höger, S., Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, 53121, Germany; Vogelsang, J., Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Regensburg, 93053, Germany; Lupton, J.M., Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Regensburg, 93053, Germany
推荐引用方式 GB/T 7714	Wilhelm P.,Schedlbauer J.,Hinderer F.,et al. Molecular excitonic seesaws[J],2018,115(16).
APA	Wilhelm P..,Schedlbauer J..,Hinderer F..,Hennen D..,Höger S..,...&Lupton J.M..(2018).Molecular excitonic seesaws.Proceedings of the National Academy of Sciences of the United States of America,115(16).
MLA	Wilhelm P.,et al."Molecular excitonic seesaws".Proceedings of the National Academy of Sciences of the United States of America 115.16(2018).