posted on 2024-01-08, 14:07authored byMengjia Yuan, Fuyin Ma, Lixi Chen, Baoyu Li, Xing Dai, Jie Shu, Linwei He, Junchang Chen, Shujing Lin, Guohua Xie, Zhifang Chai, Shuao Wang
Luminescent
covalent organic frameworks (LCOFs) have emerged as
indispensable candidates in various applications due to their greater
tunable emitting properties and structural robustness compared to
small molecule emitters. An unsolved issue in this area is developing
highly luminescent LCOFs of which the nonradiative quenching pathways
were suppressed as much as possible. Here, a robust aminal-linked
COF (DD-COF) possessing perdeuterated light-emitting monomers was
designed and synthesized. The solid-state photoluminescence quantum
yield of the DD-COF reaches 81%, significantly outcompeting all state-of-the-art
LCOFs reported so far. The exceptional luminescent efficiency is attributed
to the inhibition of different pathways of nonradiative decay, especially
from bond vibrations where only substitution by a heavier isotope
with a lower zero-point vibration frequency works. Furthermore, the
prepared deuterated COF not only boosts higher photostability under
UV irradiation but also enables superior fluorescence sensing performance
for iodine detection compared to nondeuterated COF.