Spiro-conjugated indenodiarylethenes: enabling steric-induced electronic tuning of photochromic and photoluminescent properties by spiro-conjugation  

作　　者：Tingting Huang Hongyu Liu Yawen Bang Yanpei Wang Yuan Liang Xinhao Wang Yang Zhang Sheng Xie Zebing Zeng Ben Zhong Tang 

机构地区：[1]State Key Laboratory of Chemo/Biosensing and Chemometrics,College of Chemistry and Chemical Engineering,Hunan University,Changsha 410082,China [2]Jiurui Biotechnology Co.,Ltd,Zhangjiajie 427000,China [3]Department of Chemistry,Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction,The Hong Kong University of Science&Technology,Hong Kong,China [4]Center for Aggregation-Induced Emission,SCUT-HKUST Joint Research Institute,State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,Guangzhou 510640,China

出　　处：《Science China Chemistry》2020年第11期1659-1665,共7页中国科学（化学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(51922039);Hunan Provincial Natural Science Foundation(2018JJ1008).

摘　　要：Light-operated excited-state photochemical reactions and the resulting photochromic materials have gained significant attention for their promising technological applications in molecular electronic and photonic devices.To obtain photochromic materials(e.g.,diarylethenes)with desired properties,the way to tune energy processes of the excited state is essentially important,from both fundamental and practical viewpoints.The modified diarylethenes mostly focused on structural improvements to achieve efficient photochromism.We report here two new spiro-conjugated indenodiarylethenes(named,SFI-Th and SFI-Sul)with an orthogonally arranged spiroπ-scaffold.The spiro fluorene sterically constrains the free volume of photoactive side aromatic rings,while the spiro-conjugation points toward modulation of the decaying channels of excited-state energy,thus allowing for tuning photochromic performances.These spirodiarylethenes SFI-Th and SFI-Sul are readily accessible with low cost and show distinct photochromic and photoluminescent properties.On one hand,the SFI-Th bearing bisthienyl side rings,is an excellent photochromic switch showing high thermal stability and high fatigue resistance in both solution and amorphous state,likely benefited from steric-induced excited-state energy transfer into reversible photochemical reactions,owing to higherπ-orbital spiro-conjugation between the two molecular halves.On the other hand,the SFI-Sul with bissulfonyl side rings,most notably,displays quantitative photocyclization to yield SFI-Sulc upon excitation.However,the ring-closed SFI-Sulc has an extremely slow photocycloreversion,and meanwhile immediately switches on emissive state with a strong fluorescence(Φf=0.57 in amorphous powder state).We study the modulated roles of spiroπ-scaffold in both cases computationally and experimentally,and attribute the facilitated photochemical reaction to the positively electronic effects of spiro-conjugation,and the photo-responsive radiative transition to the negatively electronic effects of sp

关 键 词：diarylethene photochromic reaction spiro-conjugation steric-induced electronic effect excited-state energy 

分 类 号：TB34[一般工业技术—材料科学与工程]