聚集诱导发光特性的杂环分子体系研究进展

Progress on heterocycle-based luminogens with aggregation-induced emission characteristics

聚集诱导发光(aggregation-induced emission,AIE)是Tang等人于2001年提出的光物理领域的一个新概念,是指一类可进行分子内转动或振动的分子体系在溶液中不发光或发光微弱,而聚集后或在固态发光显著增强的现象.由于AIE可以解决传统分子的聚集猝灭发光的难题,这一概念一经报道就引起了世界范围内科学家的兴趣.经过十余年的发展,已有几十种AIE分子体系被报道并被广泛用于有机发光二极管、传感和生物成像等领域.目前已有多篇综述全面总结了AIE领域的成果,但还没有专门的综述报道基于杂环的AIE分子体系的研究进展.本文则针对这一领域进行了较全面综述并对其未来的发展前景进行了展望.

Aggregation-induced emission （AIE）, conceptually termed by Tang et al in 2001, refers to a unique phenomenon that a series of propeller-shaped conjugated molecules are weakly or non-emissive in solution state but highly luminescent in the aggregate state. Experimental and theoretical studies have rationalized the restriction of intramolecular motion （including rotation and vibration） as the main cause for the AIE effect. Exactly opposite to conventional fluorophores that suffer from the aggregation-caused quenching （ACQ） effect, the AIE luminogens （AIEgens） could perform best in the condensed phases and enable the molecule aggregation to play positive instead of negative roles in enhancing luminescence. Attracted by this intriguing phenomenon and the application implications, scientists worldwide have actively involved in this research and promoted the development of this area. As a result, tremendous AIEgens have been synthesized and applied in optoelectronic and biologic fields etc. The progresses on the AIE have been well summarized in several excellent reviews. However, the reviewed structures of AIEgens are mostly based on the hydrocarbon ones, such as tetraphenylethene （TPE）, distyrylanthracene （DSA）, triphenylethene, tetraphenyl-l,4-butadiene （TPBD）. Herein, we mainly review the advance of heterocycle-based AIEgens containing silicon, nitrogen, sulfur, boron and phosphorus atoms etc. for the first time. The versatile properties, such as tunable emission color, good thermal and photo-stability, and the applications of these heterocycle-based AIEgens in organic light-emitting diodes, fluorescent sensors and cell imaging etc. were also briefly discussed.