Aggregation‐Induced Emission: New Vistas at the Aggregate Level

Abstract

Aggregation‐induced emission (AIE) describes a photophysical phenomenon in which molecular aggregates exhibit stronger emission than the single molecules. Over the course of the last 20 years, AIE research has made great strides in material development, mechanistic study and high‐tech applications. The achievements of AIE research demonstrate that molecular aggregates show many properties and functions that are absent in molecular species. In this review, we summarize the advances in the field of AIE and its related areas. We specifically focus on the new properties of materials attained by molecular aggregates beyond the microscopic molecular level. We hope this review will inspire more research into molecular ensembles at and beyond the meso level and lead to the significant progress in material and biological science.

Aggregate Science: From Structures to Properties

“…Such materials would have great potential for application in signal detection, information storage, etc. [255][256][257][258][259]…”

Aggregation‐Induced Emission (AIE): A Historical Perspective

“…Within the last years, the aggregation‐induced emission (AIE) phenomenon has been commemorated by several authors and publishers, most recently in a themed issue “on the 20th birthday of AIE” in Angewandte Chemie on June 15, 2020. The term AIE was coined by Ben Zhong Tang and co‐workers in 2001, and the application of this phenomenon was strongly advanced by his group as witnessed by a remarkable number of reviews . The purpose of this Essay is to provide further insights into this research field by placing it in a broader context and discussing it from a historical perspective.…”

“…Their detailed investigation of the steric and fluorescence properties of these compounds (with fluorescence quantum yields of up to 53 % for TPE 7 compared to <0.1 % for the parent TPE) concluded with the statement that phenyl ring torsional motion plays a significant, if not primary, role in the photochemistry of TPEs. Accordingly, the RIM/RIR/RIV mechanisms have been known for a long time and were applied by researchers working with stilbenes in a similar sense as done more recently in AIE research, that is, by restricting vibrational and rotational motion by intra‐ or intermolecular interactions provided by viscous environments or by chemical bonds …”

Aggregations‐induzierte Emission (AIE): Eine historische Betrachtung

“…Juni 2020. Der Ausdruck AIE wurde von Ben Zhong Tang und Mitarbeitern 2001 eingeführt und die Anwendung dieses Phänomens wurde durch seine Gruppe stark weiterentwickelt, was sich in einer beachtlichen Zahl an Übersichtsartikeln widerspiegelt . Das Ziel dieses Essays ist es, weitere Einblicke in dieses Forschungsfeld zu geben, indem es in einen breiteren Kontext gesetzt wird und aus einer historischen Sichtweise heraus erörtert wird.…”

“…Durch ihre detaillierten Untersuchungen der sterischen sowie der Fluoreszenzeigenschaften dieser Verbindungen (mit Fluoreszenzquantenausbeuten bis zu 53 % für TPE 7 im Vergleich zu <0.1 % für das reine TPE) kamen sie zu dem Schluss, dass die Torsionsbewegung der Phenylringe eine erhebliche, wenn nicht sogar die vorrangige Rolle in der Photochemie der TPEs spielt. Demzufolge waren RIM/RIR/RIV‐Mechanismen schon lange bekannt und wurden von Wissenschaftlerinnen und Wissenschaftlern, welche mit Stilbenen arbeiteten, in analoger Weise angewandt wie in jüngerer Zeit in der AIE‐Forschung, also durch Einschränkung der Schwingungs‐ und Rotationsbewegung mittels intra‐ und intermolekularer Wechselwirkungen in viskoser Umgebung oder durch chemische Bindungen …”