title: Theoretical studies on structures and aromaticity of finite-length armchair carbon nanotubes.
abstract: [structure: see text] Depending on the exact length of the tube, the chemical structure of finite-length armchair [n,n] single-wall carbon nanotube (n = 5 and 6) falls into three different classes that may be referred to as Kekulé, incomplete Clar, and complete Clar networks. The C-C bond lengths, nucleus-independent chemical shift analysis, and orbital energies suggest that the chemical reactivities of the finite-length tube change periodically as the tube length is elongated by one-by-one layering of cyclic carbon array.
authors.affiliation: Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Kazukuni
authors.initials: K
authors.lastname: Tahara
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakamura