π-Conjugated molecules covered by permethylated cyclodextrins

Insulated π-conjugated molecules, in which the π-conjugated compounds are covered by a cyclic protective sheath, have attracted considerable attention because of their potential applicability in next-generation mono-molecular electronic devices. We have developed new methods of synthesizing insulated π-conjugated molecules involving the self-inclusion of rotaxane precursors linking π-conjugated units as a guest and permethylated cyclodextrin (PMCD) as a macrocyclic host. The insulated π-conjugated molecules thus formed are highly soluble in organic solvents and display photoluminescence efficiency. This paper also highlights a new method for synthesizing insulated molecular wire (IMW) through the polymerization of insulated π-conjugated molecules as monomers. The IMWs thus formed have a high covering ratio, rigidity, and showed high charge mobility in the solid state; further, they are readily soluble in a variety of organic solvents. In this account, the synthetic methodologies and characteristic of insulated π-conjugated molecules and IMWs are discussed.