title: Azaphenalene phthalocyanines: phthalocyanine analogues with six-membered-ring units instead of five-membered-ring units.
abstract: Mixed-condensation reaction of 1,8-naphthalenedicarbonitrile and a 4,5-disubstituted phthalonitrile provided a series of phthalocyanine (Pc) analogues with azaphenalene (AP) moieties in place of the isoindole moieties. Monosubstituted species, APPc, and the two structural isomers of disubstituted species, adj-AP(2)Pc and opp-AP(2)Pc, were successfully isolated by gel-permeation chromatography on HPLC apparatus. Their structures were elucidated by (1)H NMR spectroscopy and X-ray crystallographic analysis. Replacement of the isoindole moieties with azaphenalene moieties created six-membered-ring units in the core and caused distortion of the molecular structures. The Q-band absorption shifted to the red upon an increase in the number of azaphenalene units; the shape of the absorption spectra depended on the molecular symmetries. APPc and opp-AP(2)Pc showed a large splitting of the Q band, whereas adj-AP(2)Pc exhibited a single broad Q band. These changes in the absorption spectra, as well as the unique electronic structures, are discussed in detail, based on magnetic circular dichroism spectra, electrochemical measurements, and density functional theory calculations.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, 980-8578 Japan.
authors.forename: Soji
authors.initials: S
authors.lastname: Shimizu
authors.forename: Hua
authors.initials: H
authors.lastname: Zhu
authors.forename: Nagao
authors.initials: N
authors.lastname: Kobayashi