Anion-induced opposite mechanochromic and thermochromic emission directions of protonated hydrazones  

阴离子诱导的多色发光质子化腙及其可控的机械及热致变色

作　　者：Cheng Qian Lixia Xie Lijie Liu Zhanqi Cao Dongjie Tian Dongdong Sun Guoxing Liu Zhiqian Guo Xin Zheng 钱程;谢黎霞;刘立杰;曹占奇;田东杰;孙冬冬;刘国星;郭志前;郑昕(Department of Applied Chemistry,Henan Agricultural University,Zhengzhou 450002,China;School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]Department of Applied Chemistry,Henan Agricultural University,Zhengzhou 450002,China [2]School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China

出　　处：《Science China Materials》2025年第1期125-131,共7页中国科学(材料科学)(英文版)

基　　金：financially supported by the National Natural Science Foundation of China (U20041101, 21772034, and 22305070);Top-Notch Personnel Fund of Henan Agricultural University (30500418 and 30501032);Scientific and Technological Project of the Henan Province of China (222102240043)。

摘　　要：Smart materials with tunable multiple-color emissions have been widely investigated in the fields of bioimaging,display,and information encryption.Herein,multicolor emissive molecules with hydrazone bridged triphenylamines and pyridinium groups are reported.The protonation of the pyridine subunit by various acids leads to aggregation-induced emission with broad emission colors ranging from blue to red in multiple states and spectra ofλPL,dichloromethane solution=463±584 nm,λPL,powder=455±620 nm,andλPL,crystal=485±657 nm,respectively.Upon grinding or heating,hydrazone with CF_(3)COO−exhibit blueshift emissions from red to yellow due to weakened molecular packing and conformational rigidity.In contrast,hydrazone with(CF_(3)SO_(2))_(2)N−exhibited redshift emission from green to yellow due to the decreased electron-donating ability of the triphenylamine unit upon transformation from a rigid pyramidal shape to a planar structure.These are rare,charged organic examples exhibiting predictable mechanochromic and thermochromic strong emissions through facile anion exchanges,potentially providing new insights into the design of smart materials.可控的多色发光材料在生物成像、有机光电器件、生物传感和防伪等领域具有重要应用,但目前仍难以定向开发多色发光材料.为了解决这一问题,本文以腙键为桥连接供电子性的三苯胺和吸电子性的吡啶基团,构建了一系列基于不同阴离子的D–π–A型化合物1a–1d.其中, 1b晶体能够发生力和热致荧光蓝移,从红到黄色发光.相反, 1d晶体能够发生力和热致荧光红移,从绿到橙色发光.结构分析表明, 1b中的阴离子有利于阳离子发光团的刚性平面结构,增强了三苯胺的供电子能力和分子间弱相互作用,使晶态1b具有强红光发射.而1d中的阴离子使三苯胺供体围绕中心氮原子呈锥形结构,降低了三苯胺的供电子能力,使其发绿色荧光.该工作为定向力和热致变色型多色发光材料的开发提供了新的思路.

关 键 词：multicolor emission mechanochromism THERMOCHROMISM EMISSION single crystal 

分 类 号：TB34[一般工业技术—材料科学与工程]