Synthesis And Properties Study Of Perylene-based Molecules Functionalized By Amide Nitroxide Radical

Organic functional molecules have attracted much attention due to their distinctive chemical and physical properties,and their advantages of easy structural modification,wide range of sources,rich functionalization modes.Conjugated molecules incorporating photoelectromagnetic properties have become promising organic materials.However,realizing functional design and controllable synthesis of conjugated molecules is the key point in the research of new molecular materials.Perylene has a large π-conjugation system with excellent photothermal stability among conjugated molecules,and its optoelectronic properties have shown potential applications in chemical sensing,bioimaging and organic semiconductors.Although there are several sites that can be chemically modified for functional expansion in perylene molecule,the poor stereoselectivity and poor solubility of traditioal perylene cores make their functionalized construction a challenge.In this thesis,we introduced alkoxy groups at the bay-and ortho-position to construct a distorted perylene core for achieving solubility and activating modification sites;we have have successfully introduced amide groups which can form intermolecular hydrogen bonding interaction and nitroxyl radical groups as a magnetic source on the above-mentioned perylene core to construct novel perylene derivatives,which are expected to obtain photoelectromagnetic functional integration and even chiral supramolecular aggregation.The main research contents are as follows:(1)The precusor tetrabromoperylene TBP-4Br was prepared by selective intermolecular radical oxidative coupling,reduction and etherification with2,7-dihydroxynaphthalene as starting material.On the basis of this precusor,the diagonally functionalized molecule TBP-4NO was obtained by substituting the bromine atom at the ortho-position with amide nitroxide radical groups;meanwhile,by replacing the bromine atom on the ortho-position with methoxy and further selectively brominating on the peri-position,we then introduced amide nitroxide radical groups to construct the longitudinally extended functional molecule TBP-2NO.(2)Using TBP-2NO and TBP-4NO as model compounds,we have characterized their chemical structures and photoelectromagnetic properties.The experimental results showed that TBP-2NO and TBP-4NO possessed strong solution-state fluorescence emission with absolute fluorescence quantum efficiencies of 74% and27%,respectively.Notably,they exhibited circular dichroic absorption in polar solvents at high concentrations,which may originate from the supramolecular chiral self-assembly of distorted perylene core induced by intermolecular hydrogen bonding interactions.Meanwhile,TBP-2NO and TBP-4NO exhibited multilevel reversible redox properties,which are attributed to the good electron gaining and losing ability of the radical-modified conjugated molecules.In addition,both of them showed strong electron spin resonance responses in solid and solution state,indicating their strong magnetic properties.(3)The distorted perylene core was functionalized with nitronyl nitroxide radical units,for exploring intermolecular spin-spin interactions and hydrogen bonding synergy,which possibly modulate magnetic properties in aggregated state to develop magnetostable functional aggregate materials.