Controlling quantum interference patterns in redox-active rings

• Synthetic routes to novel linear, branched, and cyclic Ru(1,2-bis(diphenylphosphino)ethane) 2 -containing molecules, including the variation of surface binding groups. • Theoretical calculations suggest that cyclic derivatives exhibit higher conductance compared to their linear counterparts due to quantum interference effects. • It has been demonstrated that conductance of both linear and cyclic molecules can vary depending on their orientation. • The nature of the anchor groups can control the orientation of the molecule in a junction, which in the case of a large tilt angle enhances the magnitude of the conductance but changes the quantum interference behavior. • The study represents the first efforts to explore QI effects in Magoga-Joachim type systems comprising tunable transport pathways through each branch of a cyclic system. The ability to create molecules, which exhibit tunable and unique conductive properties is a key requirement for the development of future generation devices. Towards this concept, we herein report synthetic routes to novel linear, branched, and cyclic Ru(1,2-bis(diphenylphosphino)ethane) 2 -containing molecules, including the variation of surface binding groups. Synthetic strategies are discussed followed by a discussion of the electrochemical properties of the molecules. Theoretical calculations suggest that cyclic derivatives exhibit higher conductance compared to their linear counterparts due to quantum interference effects. Additionally, the conductance of both linear and cyclic molecules can vary depending on their orientation.