ABSTRACT
This chapter focuses on the synthesis, secondary structure, and functions of polyacetylene and foldamers known as dynamic helical -Ç-conjugated polymers. The preferred handedness was detected immediately, creating characteristic circular dichroism (CD) signals in the p-conjugated main-chain absorption regions. A good relationship was observed between the signs of CD signals corresponding to the polymer helicity and the absolute configurations of chiral additives. Amino acids and peptide residues, which represent a versatile source of chirality in organic synthesis, have been incorporated in several helical p-conjugated polyacetylenes as pendant groups. The tuning of p-conjugated arylene units of main chains including biphenyl, naphthalene, pyrene, and azobenzene enabled to control the conjugation lengths of obtained helical foldamers. The chapter reviews the synthesis, secondary structures, and functions of polyacetylene and p-conjugated foldamers. The research area reviewed here has remarkably developed over the past decade, and a large number of helical polyacetylenes and foldamers have been synthesized.
