Time-dependent color-tunable room temperature phosphorescence from unusual conformational transitions in phenothiazine polymers under UV irradiation  

作　　者：Jiwen Lu Yifan Niu Chanjuan Jin Chengheng Wu Hanyu Wang Yan Guan Ping Wang Xinghe Fan 

机构地区：[1]Key Lab of Environment-Friendly Chemistry and Application of Ministry of Education,Key Laboratory of Polymeric Materials and Application Technology of Hunan Province,Key Laboratory of Advanced Functional Polymer Materials of Colleges,Universities of Hunan Province,College of Chemistry,Xiangtan University,Xiangtan 411105,China [2]Beijing National Laboratory for Molecular Sciences,Key Laboratory of Polymer Chemistry and Physics of Ministry of Education,Center for Soft Matter Science and Engineering,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China

出　　处：《Science China Chemistry》2025年第3期1091-1098,共8页中国科学(化学英文版)

基　　金：supported by the National Natural Science Foundation of China (22175149);the Natural Science Foundation of Hunan Province (NSFH 2021JJ30661)。

摘　　要：Achieving color-tunable room-temperature phosphorescence(RTP),especially including blue RTP from a single-component polymer still faces a formidable challenge.Herein,we wisely choose conformation-dependent phenothiazine with trifluoromethyl substituent as the side group of the phosphor monomer(Cz PT)and then copolymerize it with N-isopropylacrylamide(NIPAM)through photopolymerization to obtain polymers PPCz PTs.Time-dependent color-tunable phosphorescence from unusual quasi-equatorial(eq)to quasi-axial(ax)conformers are obtained,and the RTP color changes from orange(550 nm)to blue(470 nm)with phosphorescence lifetime up to 0.96 s.The theoretical calculations confirm that the quasi-axial conformer is the preferred structure that facilitates the formation of intramolecular hydrogen bonds on the trifluoromethyl group.The EPR spectra illustrate that the persistent UV irradiation generates radical cations to induce the conformational transitions first,followed by photopolymerization immobilizing the ax conformation in PPCz PTs.Applications of data encryption and anti-counterfeiting are fabricated to show prompt and delayed multicolor information.This work affords a simple and feasible avenue for two-dimensional color tunable room temperature phosphorescence from a single-component polymer.

关 键 词：polymeric room temperature phosphorescence color-tunable phosphorescence conformation-dependent TIME-DEPENDENT blue phosphorescence 

分 类 号：TQ317[化学工程—高聚物工业]