Multifunctional Thermally Activated Delayed Fluorescence Emitters and Insight into Multicolor‐Mechanochromism Promoted by Weak Intra‐ and Intermolecular Interactions. Issue 22 (20th August 2019)

• Record Type: Journal Article
• Authors: Zheng, Kailu; Yang, Hannan; Ni, Fan; Chen, Zhanxiang; Gong, Shaolong; Lu, Zhenghong; Yang, Chuluo
• Is Part Of: Advanced optical materials. Volume 7:Issue 22(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-20
• Subjects: aggregation induced emission -- delayed fluorescence -- mechanochromism -- organic light‐emitting diode; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201900727
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Two multifunctional emissive molecules (QBP‐DMAC and QBP‐PXZ) with a novel accepting unit (5, 6‐dihydropyrrolo[2, 1‐ a ]isoquinoline‐1, 3‐diyl)bis(phenylmethanone) (QBP) are designed and synthesized. Both emitters exhibit thermally activated delayed fluorescence (TADF) and aggregation‐induced emission characteristics, and QBP‐DMAC shows multicolor mechanochromic luminescent (MCL). Intriguingly, crystal structure of QBP‐DMAC reveals loose molecular packing mode and slipped π–π intramolecular interactions between DMAC moieties, which are identified as the underlying mechanism for its MCL behavior. Moreover, the QBP‐DMAC‐based organic light‐emitting diode device achieves high external quantum efficiencies up to 18.8%, which is among the highest efficiencies for the MCL‐active TADF emitters. Abstract : Two butterfly‐shaped thermally activated delayed fluorescence (TADF) molecules, QBP‐DMAC and QBP‐PXZ are designed and synthesized. QBP‐DMAC exhibits remarkable multicolor changing behavior. The QBP‐PXZ and QBP‐DMAC‐based organic light‐emitting diodes (OLED) devices achieved external quantum efficiencies of 16.6% and 18.8% for yellow and green OLEDs, respectively.