‘Paddle-wheel’ hydrocarbons. Intracyclic C–C bond length shortening in rotanes. X-Ray crystal structures of [3]- and [4]-rotane
Abstract
Single crystal X-ray determinations of the structures of [3]- and [4]-rotane reveal that bond-length shortening occurs in the inner central cyclopropane or cyclobutane ring; this may be attributed to a π bond order enhancement resulting from the disposition of the adjacent (paddle-like) peripheral cyclopropane rings.