Synthesis Of Tetraphenylethylene Crown Ether Acetylene Macrocycles And Chiral Acid-Inspired Chiral Optical Properties

Aggregation-induced luminescence refers to a special photophysical phenomenon in which a fluorescent compound does not emit light in a dilute solution but emits strong fluorescence in a high concentration or in a solid state.As the AIE phenomenon has important potential applications in photovoltaic functional materials,it has attracted extensive attention from researchers at home and abroad.Tetraphenylethylene and its derivatives have become the most studied AIE compounds due to their high molecular symmetry,simple synthesis,and ease of modification.At the same time,since the benzene ring in tetraphenylethylene has a propeller-like structure,a single left helix or right helix structure can be obtained.In this dissertation,a series of crown ether-modified tetraphenylethylene rings were synthesized by modification of TPE molecules.Under the induction of chiral acids,the helical chiral optical properties are shown.1.Using 4-bromo-4’-hydroxybenzophenone as a raw material,nucleophilic substitution reaction with pentaethylene glycol di-p-toluene sulfonic acid first,followed by intramolecular McMurry reaction,to obtain crown ether modified TPE dibromo products,then it reacted with the starting material 2-methyl-3-butyn-2-ol to give mono-and di-substituted products.The mono-substituted product is synthesized via a Sonogashira coupling reaction to a rigid TPE with a single acetylene bridge ring.The product of the double substitution first removes two molecules of acetone under the action of a strong base,and then an intermolecular Eglinton reaction occurs to synthesize a rigid TPE macrocycle bridged with a diacetylene group.2.Synthesis of three crown ether-modified tetraphenylethylene rigid macrocycles.A series of intermediates and macrocycles were systematically characterized by means of nuclear magnetic resonance spectroscopy(¹H NMR and ¹³C NMR),infrared spectroscopy,melting point and high resolution mass spectrometry.At the same time,the single crystal structure of rigid TPE macrocycles bridged by monoacetylene groups was obtained.The macrocyclic compounds were all found to be typical AIE compounds by fluorescence measurement,and all had high relative fluorescence quantum yields.3.Under the effect of chiral acid induction,the membranes prepared by the solvent evaporation method of rigid TPE macrocycles bridged by chiral acids and monoacetylene radicals have perfectly symmetrical CD and CPL signals,and are found through TEM studies,the reason for the chirality is that the propeller structure of the benzene ring in the TPE is induced to a single left helix or right helix.