Keto-form directed hierarchical chiral self-assembly of Schiff base derivatives with amplified circularly polarized luminescence  

作　　者：Yimeng Sun Yuqian Jiang Jian Jiang Tiesheng Li Minghua Liu 

机构地区：[1]Green Catalysis Center,and College of Chemistry,Zhengzhou University,Zhengzhou 450001,China [2]Key Laboratory of Nanosystem and Hierarchical Fabrication,CAS Center for Excellence in Nanoscience,National Center for Nanoscience and Technology,Beijing 100190,China [3]National Laboratory for Molecular Science(BNLMS),CAS Laboratory of Colloid,Interface and Chemical Thermodynamics,Institute of Chemistry,Chinese Academy of Science,Beijing 100190,China [4]University of Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Chinese Chemical Letters》2024年第1期366-370,共5页中国化学快报（英文版）

基　　金：National Natural Science foundation of China(Nos.21861132002,21773043,21973020 and 21890734).

摘　　要：While enol-keto tautomerism has attracted great interest in Schiff bases and related compounds in solution and crystal states,the self-assembly of energy-unfavored keto form were scarcely investigated.Here,we report a keto-form directed self-assembly of a naphthalene-attached enantiomeric N-salicylideneanil analog L/DGG-Nap accompanied with a significantly amplified circularly polarized luminescence(CPL).It was found that LGG-Nap exists as a mixture of enol and keto form in monomer at a diluted toluene solution.The increment of the concentrations leads to the formation of predominated keto form,which subsequently triggers the self-assembly.Cryo-transmission electron microscopy(Cryo-TEM)revealed that a hierarchical assembly process happened upon increasing the concentration of LGG-Nap in toluene.Individual nanofibers formed at 1×10-4 mol/L and transferred into helical nanofiber bundles in 5×10-3 mol/L.Interestingly,while these is nearly no circular dichroism(CD)or CPL in the monomeric solution,the assembly showed strong CD and CPL.Remarkably,the dissymmetry factor(glum)was significantly amplified from zero in solution through the 0.005 in individual nanofiber to 0.1 in nanofiber bundles.This work demonstrates that the enol-keto tautomerism can be broken and trigger the self-assembly upon increasing the concentration,which can subsequently direct the chiral self-assembly and significantly amplify the dissymmetry factor of assembled CPL materials.

关 键 词：Enol-keto tautomerism Chiral self-assembly Schiff base Circularly polarized luminescence Nanofiber bundle 

分 类 号：TB34[一般工业技术—材料科学与工程]