Nanoribbons, the bottom-way up
04 February 2014 - Nano
A previous episode of this blog reported on the synthesis of nanotubes starting from 12-cycloparaphenylene. In a very new bottom-up approach described here the starting material for a closely related nanoribbon is a slightly modified tetraphenylcyclopentadienone. Added functional group is an alkyne group and by polymerization at 250°C alkyne and cyclopentadienone combine in a Diels-Alder reaction to a polyphenylene. A second cyclodehydrogenation step (Scholl reaction) with ferric chloride in dichloromethane at rt for 3 days assembles the planar nanoribbons. The final dimensions of the nanoribbons have been reported as 1 by 200 nanometers and with hairs because the monomer has two dodecyl units stuck to it. These hairs enable the ribbons to disperse in an ordinary solvent such as THF.