π共轭聚合物聚集体中J型和H型耦合之间的相互作用：单分子视角

Eder Theresa, Vogelsang Jan, Bange Sebastian, Remmerssen Klaas, Schmitz Daniela, Jester Stefan-S, Keller Tristan J, Höger Sigurd, Lupton John M

Institut für Angewandte und Experimentelle Physik, Universität Regensburg, Universitätsstrasse 31, 93053, Regensburg, Germany.

Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.

Angew Chem Int Ed Engl. 2019 Dec 19;58(52):18898-18902. doi: 10.1002/anie.201912374. Epub 2019 Nov 6.

Strong dipole-dipole coupling within and between π-conjugated segments shifts electronic transitions, and modifies vibronic coupling and excited-state lifetimes. Since J-type coupling between monomers along the conjugated-polymer (CP) chain and H-type coupling of chromophores between chains of a CP compete, a superposition of the spectral modifications arising from each type of coupling emerges, making the two couplings hard to discern in the ensemble. We introduce a single-molecule H-type aggregate of fixed spacing and variable length of up to 10 nm. HJ-type aggregate formation is visualized intuitively in the scatter of single-molecule spectra.

π共轭片段内部以及之间的强偶极-偶极耦合会使电子跃迁发生位移，并改变振子强度耦合和激发态寿命。由于沿着共轭聚合物（CP）链的单体之间的J型耦合与CP链之间发色团的H型耦合相互竞争，每种耦合产生的光谱变化叠加在一起，使得在整体中难以区分这两种耦合。我们引入了一种固定间距且长度可变、最长可达10 nm的单分子H型聚集体。在单分子光谱的散射中直观地观察到了HJ型聚集体的形成。