Self-Assembled nanotubes and nanocoils from π-conjugated building blocks

This review article describes recent studies on the self-assembly and co-assembly of π-conjugated molecules into nanotubes and nanocoils. Such π-conjugated molecules include phenylenes, phenylene vinylenes, phenylene ethynylenes, porphyrins, phthalocyanines, and polycyclic aromatic hydrocarbons, which are properly modified with hydrophilic and/or hydrophobic side chains for cooperative interactions. Not only nanocoils but also most reported nanotubes possess a helical chirality. These assembling events possibly show chiral amplification, where one-handedness can be realized even from stereochemically impure components (majority rule). Combination of components leading to non-tubular assemblies with properly chosen chiral components may give rise to nanotubes or nanocoils with one-handed helical chirality (sergeants-and-soldiers effect). Covalent modification of assembled components can enhance physical robustness against heating and solvolysis. © 2008 Springer Berlin Heidelberg.