Key Laboratory for Organic Electronics & Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjin, China.
Phys Chem Chem Phys. 2012 Apr 21;14(15):5289-96. doi: 10.1039/c2cp23040b. Epub 2012 Mar 9.
An anthracene carboxamide derivative of the excited-state intramolecular proton-transfer compound of 2-(2'-hydroxyphenyl)benzothiazole has been newly developed to produce the prominent characteristics of aggregation-induced enhanced emission (AIEE) with a high solid-state fluorescence quantum efficiency of 78.1%. Compared with our previously reported phenyl carboxamide derivatives, a small tailoring of the molecular structure was found to result in a big difference in the dominant factor of the AIEE mechanism. In the phenyl carboxamide derivatives, the dominant factor of the AIEE mechanism is the restriction of the twisted intramolecular charge transfer (TICT) of the enol excited state, regardless of their different aggregation modes. In the anthracene carboxamide derivative, N-(3-(benzo[d]thiazol-2-yl)-4-hydroxyphenyl) anthracene-9-carboxamide, the AIEE characteristics are not dependent on the restriction of TICT, but mainly attributed to the cooperative effects of J-aggregation and the restriction of the cis-trans tautomerization in the keto excited state. A specific N···π interaction was found to be the main driving force for this J-aggregation, as revealed by the single crystal analysis. The AIEE mechanism of this anthracene carboxamide derivative was studied in detail through photophysical investigations and theoretical calculations. On the basis of its AIEE characteristics, a stable non-doped organic light-emitting diode was achieved, with high color purity and a remarkably low efficiency roll-off.
一种蒽酰胺衍生物的激发态分子内质子转移化合物 2-(2'-羟基苯基)苯并噻唑具有显著的聚集诱导增强发射（AIEE）特性，其固态荧光量子效率高达 78.1%。与我们之前报道的苯基酰胺衍生物相比，对分子结构进行了微小的修饰，发现 AIEE 机制的主导因素有很大的不同。在苯基酰胺衍生物中，AIEE 机制的主导因素是对烯醇激发态的扭曲分子内电荷转移（TICT）的限制，而不管它们的聚集模式有何不同。在蒽酰胺衍生物 N-(3-(苯并[d]噻唑-2-基)-4-羟基苯基)蒽-9-甲酰胺中，AIEE 特性不依赖于 TICT 的限制，而是主要归因于 J-聚集和酮激发态中顺反互变异构的限制的协同作用。通过单晶分析发现，特定的 N···π 相互作用是这种 J-聚集的主要驱动力。通过光物理研究和理论计算详细研究了这种蒽酰胺衍生物的 AIEE 机制。在此基础上，实现了一种具有高色纯度和显著低效率滚降的稳定无掺杂有机发光二极管。
