Chemically and electrochemically induced expansion and contraction of a ferrocene rotor

Abstract

A 2,2′-bipyridine-appended ferrocene rotor, 1,1′-di(5-yl-ethynyl-2,2′-bipyridine)ferrocene, can be switched from a folded/stacked (syn) conformation to an extended/unstacked (anti) conformation by the addition of [Cu(CH₃CN)₄](PF₆) and 6,6′-dimesityl-2,2′-bipyridine. This extension and contraction process was completely reversible and could be triggered either chemically or electrochemically.