Enhancing Effect of Fullerene Guest and Counterion on the Structural Stability and Electrical Conductivity of Octahedral Metallo‐Supramolecular Cages

Abstract

Metallo‐supramolecular cages have garnered tremendous attention for their diverse yet molecular‐level precision structures. However, physical properties of these supramolecular ensembles, which are of potential significance in molecular electronics, remain largely unexplored. We herein constructed a series of octahedral metallo‐cages and cage‐fullerene complexes with notably enhanced structural stability. As such, we could systematically evaluate the electrical conductivity of these ensembles at both single‐molecule level and aggregated bulk state (as well‐defined films). Our findings reveal that counteranions and fullerene guests play a pivotal role in determining the electrical conductivity of aggregated state, while such effects are less significant for single‐molecule conductance. Both counteranions and fullerenes effectively tune the electronic structures and packing density of metallo‐supramolecular assemblies, and facilitate efficient charge transfer between the cage hosts and fullerenes, resulting in a notable one order of magnitude increase in electrical conductivity of the aggregated state.