A Macrocyclic Compound Based On Donor-acceptor Interaction And Its Photochemistry

The potential applications of macrocyclic compounds with host-guest interactions have received increasing attention in the field of supramolecular chemistry.The well-defined structure and the inclusion by cyclic cavity allow the macrocyclic host to complex with various inorganic/organic/bio molecules and ions in the solution or solid state.It is widely used not only as a receptor unit for molecular recognition,but also as building blocks for fabricating nanostructured functional materials.As the bridge of light and chemical change,photoreactive group is the basis of regulating the morphology transformation of assembly,and the innovation of its chemical structure is the driving force for the development of photo-controlled self-assembly.In our work,a photo-responsive macrocyclic host was designed and synthesized.It will generate photocatalytic cation radical through photoinduced electron transfer（PET）due to the D-A interaction.Meanwhile,the photodegradation will be stimulated after complexing different guest units,which has broad application prospects in the fields of photodegradable materials,targeted drug delivery,and artificial photosynthesis.1.A macrocyclic compound containing D-A structure was synthesized,consisting of an electron-rich donor unit alkoxyanthracene（An）,linking group glycol chains,and an acceptor unit 4,4-bipyridinium salt（MV）.Due to the presence of D-A structure,the density of electron cloud on the alkoxyanthracene can be effectively reduced,which renders the host highly photo-inert.However,the photoactivity of the alkoxyanthracene will be renewed after complexing with a stronger electron-donating guest,giving photolytic host–guest complex or aggregate.This host–guest system provides a new train of thought for photo-responsive self-assemblies,and exhibits promising applications for photo-controlled drug delivery and molecular switching in the future.2.Benefiting from the D-A structure and the excellent photo-stability of AnMV,it was applied in photocatalytic redox reaction.The An radical in AnMV,produced during the intramolecular photoinduced electron transfer（PET）,can grasp an electron from the exogenous electron-donating agent（triethanolamine,TEOA）.It eventually generates a stable viologen cation radical(MV^+·),which can further reduce the Fe（Ⅲ）in Cytochrome c.In other words,AnMV was successfully used to achieve the photocatalytic reduction of cytochrome c.Compared with the noncyclic analogue and a viologen without An unit,the cyclic AnMV has a higher catalytic efficiency.This work not only enriches the types of photo-redox catalysts,but also has potential applications in the field of artificial photosynthesis.