Synthesis And Application Of Stable Organic Radicals

The history of radical chemistry can be traced back to the nineteenth century.Radical chemistry has achieved unprecedented development in this century.Related research which is the frontier and hotspot of multidisciplinary intersecting has permeated into many disciplines such as chemistry,physics,materials,biomedicine,etc.The stability of radicals has always been the focus and difficulty of radical chemistry research.Radical materials are unstable due to the active single electron of the open shell,which limits their widespread applications for the challenging synthesis.The design of this paper adopts conjugated structures,large blocking groups and heteroatoms to stabilize radicals and develop novel covalent macrocycle radicals.The main goal of this paper is to build a stable organic radical system,including radical small molecules,radical covalent macrocycles and polymers,and explore their potential applications.Firstly,three kinds of persistent phenoxy radicals were designed and synthesized.Secondly,a phenothiazine-based radical covalent macrocycle was designed and synthesized.Finally,a new type of supramolecular radical polymer was designed and constructed.In addition,this paper also systematically studies the physicochemical properties of the target compounds and discusses the potential scientific applications of such materials.Specifically,this paper includes the following four chapters.Chapter one introduces the historical background of radical chemistry and the research progress of radical chemistry in recent years.This chapter also details the research progress of supramolecular radical chemistry,which is a new frontier research direction.On this basis,the research topics of this thesis are proposed.Chapter two introduces the design and synthesis of phenoxy small radicals.The main strategy is to stabilize such radical small molecules by adopting conjugated structures,large blocking groups and heteroatoms,whose properties are also studied.In addition,this chapter also discusses the potential application of such radicals in proton-coupled electron transfer reactions.This work provides new ideas for designing a new and stable phenoxy radical system.Chapter three introduces the design and synthesis of a phenothiazine-based radical covalent macrocycle.The main strategy is to stabilize the phenothiazine-based radical covalent macrocycle through the closed shell structure formed by the conjugation effect.This chapter also explores the potential application of these materials as cathode materials in lithium ion batteries.This work provides a good reference for the subsequent improvement of the properties of lithium ion battery radical materials.Chapter four introduces the design and synthesis of a new type of supramolecular radical polymer.The main strategy is to construct a new type of supramolecular radical polymer through the halogen bonding interaction between radicals and halogen atoms by modifying the nitroxide radicals on pillar[5]arene covalent macrocycles.This work provides new material basis for the design of new supramolecular radical materials.