Synthesis Of AIE-active Macrocyclic Compounds And The Construction Of Artificial Light-harversting Systems For Photochemical Catalysis

Macrocyclic compounds have been widely used in molecular recognition,drug transport, gas adsorption,chemical sensors and biological imaging.Nowadays,the energy problem has become a major crisis in human society.Efficient light harvesting system is of great significance for natural photosynthesis using solar energy and searching for new green energy sources.At present,there are few reports on artificial light harvesting system based on macrocyclic compounds,and the construction of multi-step energy transfer system simulating natural photocatalytic process is still facing great challenges.Herein,we report a quadrilateral platinum(II)metallacycle containing tetraphenylethylene(M1)and organic marcocyclic compound(M2)as light-harvesting platform.The content of this thesis is divided into four parts:Part I:Synthesis of a AIE-active platinum(?)metallacycle M1.(1)compound 3 was synthesized from 3,5-dibromobenzic acid and 18-alkylamine by amide condensation.Miyaura cross-coupling reaction was achieved to give compound 4.(2)Compound 5 was synthesized from diphenylmethane and 1,4-dibromophenone.Compound 5 reacted with p-ethynylpyridine by Sonogashira coupling reaction to form compound 6.(3)Hemicyclic compound 7 was synthesized by Suzuki-coupling reaction between 4 and 6.(4)Compound 7 and trans platinum(?)ligand via[2+2]coordination driven self-assembly to form metallcycle M1.Part?:Synthesis of a AIE-active organic macrocycle M2.(1)Compound 9 was synthesized by Suzuki-coupling reaction between 4 and 5-bromo-2-iodopyridine.(2)Compound11 was obtained by Suzuki-coupling reaction between 9 and compound 10.In the presence of tetrabutylammonium fluoride,the terminal trimethylsilyl protecting group was removed to form compound 12.M2 was obtained by intermolecular polymerization.Part?.In MeOH/H₂O(1:19,v/v),M1 was used to construct an artificial light harvesting system with eosin(ESY)and sulforhodamine(SR101).One-step light harvesting system M1-ESY and M1-SR101 have been successfully constructed.The energy transfer efficiency and antenna effect of M1-ESY system are better than those of M1-SR101 system.With ESY as a relay and SR101 as the second energy acceptor,two-step sequential energy transfer process can be realized from M1 assembly to ESY and then to SR101.Compared with M1-SR101system,M1-ESY-SR101 system shows better energy transfer efficiency and antenna effect.By adding different proportion of acceptor dyes,the color-tunable including white light was realized.Finally,the M1-ESY-SR101 system was utilized as photochemical catalysis for alkylation of C-H bonds in aqueous solution,showing enhanced catalytic activity,as compared with M1-ESY system or ESY/SR101 alone.Part?.In THF/H₂O(1:19,v/v),M2 was used to construct artificial light harvesting system with dyes.M2 can construct one-step light harvesting system with ESY.However,the sequential energy transfer phenomenon can be negligible by adding the second acceptor SR101.