近日，2021级毕业硕士生万海斐同学在SCI一区期刊Advanced Optical Materials (IF=8.0) 发表基于调控连接体的共轭和柔性来增强聚集诱导发光共价有机框架的发光性能“Modulating Linker Conjugation and Flexibility of Aggregation-Induced Emission Covalent Organic Framework for Enhanced Luminescence”。

原文链接：https://doi.org/10.1002/adom.202402907

Abstract

In order to inhibit non-radiative decay pathways of covalent-organic frameworks (COFs), a strategy was proposed to block intralayer conjugation and interlayer π-π stacking by using flexible aggregation-induced emission (AIE) building blocks (4',4''',4''''',4'''''''-(1,2-ethenediylidene) tetrakis[1,1'-biphenyl]-4-carbaldehyde (TFBE)) connected by weakly conjugated flexible linker. By using the flexible TFBE as building blocks and changing the conjugation and flexibility of linker, TFBE-COFs with different luminescence properties were obtained. Experimental and theoretical results showed that these TFBE-COFs have high crystallinity and large layer spacing, among which the photoluminescence quantum yield of hydrazone (Hz)-COF_TFBE-ODH (oxalyl dihydrazide (ODH)) in solid state reached 26.28%, which was superior to most of the COFs reported so far. The excellent luminescence was attributed to the non-planar geometry and flexibility of TFBE, which inhibit aggregation-induced quenching. Moreover, the π-electron delocalization-induced non-radiative leaps were suppressed by weakly conjugated flexible linker, which further enhanced the photoluminescence of TFBE-COFs. The Hz-COF_TFBE-ODH exhibited excellent sensing performance for trace tetracycline, the detection limit was 0.15 μM. In addition, a white light-emitting diodes coated with Hz-COF_TFBE-ODH was manufactured to achieve high-quality white light emission. This study provides a new strategy for the design and application of high-emission COFs.

Scheme 1. Schematic diagram of the regulation of TFBE-COFs.