Systematic study of the structure-property relationship of a series of near-infrared absorbing push-pull heptamethine chromophores for electro-optics  

作　　者：Di Zhang Jie Zou Wen Wang Qian Yu Guowei Deng Jieyun Wu Zhong-An Li Jingdong Luo 

机构地区：[1]Shenzhen Research Institute,City University of Hong Kong,Shenzhen,518057,China [2]Department of Chemistry,City University of Hong Kong,Kowloon,Hong Kong SAR,China [3]College of Chemistry and Life Science,Sichuan Provincial Key Laboratory for Structural Optimization and Application of Functional Molecules,Chengdu Normal University,Chengdu,611130,China [4]School of Optoelectronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu,611731,China [5]Key Laboratory for Material Chemistry of Energy Conversion and Storage,Ministry of Education,School of Chemistry and Chemical Engineering,Huazhong University of Science and Technology,Wuhan,430074,China

出　　处：《Science China Chemistry》2021年第2期263-273,共11页中国科学（化学英文版）

基　　金：the Fundamental Research Project funding from Shenzhen Science&Technology Innovation Committee(JCYJ20180507181718203);the National Natural Science Foundation of China(21975213);the Research Grants Council(RGC)of Hong Kong(11306320);internal research supports or initiatives from City University of Hong Kong(9610389,9680263,9610454)。

摘　　要：This study reports the facile synthesis,characterization and quantitative structure-property relationship analysis of molecular and material properties of tricyanofuran-based(TCF)dipolar heptamethines with different electron donors of indoline(F1),benzo[e]-indoline(F2),benz[cd]indoline(F3),and Michler’s base derivatives(Ml and M2).The linear and nonlinear optical(NLO)properties of these chromophores have been thoroughly investigated,and the relationship between molecular and bulk response has been analyzed and compared with dipolar tetraene AJLZ53 as one of the best chromophores for electro-optic(EO)devices.In particular,we provide responsible data collection and analysis of optical and EO properties for poled thin films using a widelyrecognized and accredited methodology of prism coupling system with the help of rigid oriented gas model.We found that these push-pull heptamethines with synthetic efficacy exhibit high near-infrared absorption,excellent chemical stability and large hyperpolarizabilities(β)varied from 1,023×10^-30 esu for F1,3,047×10^-30 esu for M1,and 3,547×10^-30 esu for F3 at 1,304 nm in poled films,respectively.Theβvalues of these molecules are among the highest ones for TCF-based dipolar chromophores,and also agree well with reported analytical results in the solutions.In poled polymers with a modest chromophoric loading density of1.3×10^20 cm^-3,Ml and M2 give a high poled-induced noncentrosymmetric order and relatively large r33 values around40 pm V^-1 at 1,304 nm,indicative of largeμβvalues and suitable structural modification for high poling efficiency.Furthermore,a binary EO polymer based on the co-loading of Ml and AJLZ53 achieve a large r33 value of 143.3 pm V^-1 at 1,304 nm.Our studies suggest that concise synthesis and molecular design of push-pull polymethines can be well guided by the tabulation of their linear and NLO properties in bulk materials,and streamline future development of high performance organic EO materials for photonic applications.

关 键 词：ELECTRO-OPTICS Pockels coefficient HYPERPOLARIZABILITY dipolar chromophores organic nonlinear optics 

分 类 号：TB34[一般工业技术—材料科学与工程]