Synthesis and structure of built-up organic macromolecules containing helicene

Built-up macromolecules are acyclic molecules with molecular weights of several thousand daltons, which are synthesized by connecting small molecular units using stepwise methods. The chemical study of built-up macromolecules reveals some noteworthy properties that are different from those of conventional biological and synthetic macromolecules. A characteristic feature of built-up organic macromolecules is that their structures and properties are discontinuous at a certain molecular weight. For such macromolecules, variation in the small molecular units and the formation of cyclic structures substantially affect the structure and properties. The built-up organic macromolecules obtained by connecting helicenes with amide, acetylene, and amine groups are discussed in this paper. Some chiral built-up macromolecules are linked by covalent bonds, and the effects of linking on the structure are compared.