Conductance of o-carborane-based wires with different substitution patterns

Here, we report the synthesis, structure, and single-molecule conductance of three o-carborane-based molecular wires (ortho-, meta- and para-CN) with multiple conduction channels. The effect of connectivity in target wires compared with the corresponding phenyl-centered wires was studied using the scanning tunneling microscope break junction (STM-BJ) technique and theoretical calculations. Interestingly, the three-dimensional structure in o-carborane-based wires can effectively promote the through-space transmission paths or the formation of stable molecular junctions compared to the corresponding phenyl-centered wires. Moreover, the significant conductance difference of o-carborane-based wires was due to the combination of multiple conduction channels and quantum interference. Understanding the effects of different bridging groups and anchor group substitution patterns provides guidelines for designing o-carborane-based multichannel molecular wires.

Automated summary

Here, we present the synthesis, structure, and single-molecule conductance of three o-carborane-based molecular wires with multiple conduction channels. Through experimental and theoretical studies, we found that o-carborane-based wires have a unique three-dimensional structure that facilitates through-space transmission paths and stable molecular junction formation compared to phenyl-centered wires. The significant difference in conductance is attributed to the combination of multiple conduction channels and quantum interference. Understanding the impact of different bridging groups and anchor group substitution patterns provides valuable insights for designing multichannel molecular wires based on o-carboranes.