Dewar benzenoids in cyclophenacene nanobelts

Abstract

Cyclophenacene molecules are carbon nanobelts and are the smallest possible hydrogen capped armchair carbon nanotubes. In this density functional theory study Dewar benzene derivatives within cyclophenacene isomers are examined for the [n]cyclophenacenes with n = 6–14 belt sizes (for even values of n). Cyclophenacenes containing Dewar benzenoids are found to have higher energy electronic singlet-triplet state transitions compared to the purely Kekulé benzenoid isomers of the same size. The [6]cyclophenacene isomer containing two maximally spaced Dewar benzenoids is found to have a similar energy to the exclusively Kekulé benzenoid isomer and the addition of solvent is predicted to stabilize the Kekulé form.