The effect of benzo-fusion on tricyclic [10]annulenes: synthesis, properties, and X-ray structure of 9c-methyl-9cH-cyclopenta[jk]fluorene
Abstract
The benzo-fused [10]annulene (2) has been synthesised; n.m.r. spectroscopy establishes that compound retains about two-thirds of the ring current of the unperturbed annulene (1), and an accurate X-ray structure determination demonstrates the presence of some [14] annulene character.