Ferrocene-Based Nanoelectronics: 2,5-Diethynylpyridine as a Reversible Switching Element

A new strategy is presented for the construction of a ferrocene-based molecular diode that operates by an electron-hopping mechanism. Key to this design is implementation of the asymmetric 2,5-diethynylpyridine bridging unit that serves to reversibly switch the system between two states. Results of investigations of the molecular and electronic structures of the diferrocene complexes 1 and 2, which respectively serve as models for state 1 and state 2, establish that the criteria for the new strategy can likely be met with the 2,5-diethynylpyridine bridge.