Single-Molecule Nanosized Polycyclic Aromatics with Alternant Five- and Six-Membered Rings: Synthesis and Optical Properties

Abstract

A synthetic protocol for a novel family of symmetric polycyclic aromatics with a benzene or cyclooctatetraene (COT) ring as the core and alternant fused benzene and cyclopentadiene rings as branches has been developed. The TiCl₄-promoted cyclizations construct both planar trimers and tubelike tetramers via the “in situ” generation of the benzene or COT skeleton. The structures of 6b, 7a, 7b, and 10 have been characterized by ¹H and ¹³C NMR spectra and MALDI-TOF mass spectroscopy. These polycyclic aromatics also exhibit interesting optical properties.