Hestand Nicholas J, Spano Frank C
Department of Chemistry , Temple University , Philadelphia , Pennsylvania 19122 , United States.
Chem Rev. 2018 Aug 8;118(15):7069-7163. doi: 10.1021/acs.chemrev.7b00581. Epub 2018 Apr 17.
The electronic excited states of molecular aggregates and their photophysical signatures have long fascinated spectroscopists and theoreticians alike since the advent of Frenkel exciton theory almost 90 years ago. The influence of molecular packing on basic optical probes like absorption and photoluminescence was originally worked out by Kasha for aggregates dominated by Coulombic intermolecular interactions, eventually leading to the classification of J- and H-aggregates. This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated. An assortment of packing geometries is considered from the humble molecular dimer to more exotic structures including linear and bent aggregates, two-dimensional herringbone and "HJ" aggregates, and chiral aggregates. The interplay between long-range Coulomb coupling and short-range charge-transfer-mediated coupling strongly depends on the aggregate architecture leading to a wide array of photophysical behaviors.
自近90年前弗伦克尔激子理论问世以来，分子聚集体的电子激发态及其光物理特征一直吸引着光谱学家和理论家。分子堆积对吸收和光致发光等基本光学探针的影响最初是由卡沙针对以库仑分子间相互作用为主导的聚集体得出的，最终导致了J聚集体和H聚集体的分类。本综述概述了在纳入振动耦合和分子间电荷转移时，在理解聚集体结构与光物理之间关系方面取得的进展。从简单的分子二聚体到更奇特的结构，包括线性和弯曲聚集体、二维人字纹和“HJ”聚集体以及手性聚集体，考虑了各种堆积几何结构。长程库仑耦合和短程电荷转移介导的耦合之间的相互作用强烈依赖于聚集体结构，从而导致了广泛的光物理行为。
