Nanoscale Evolution of Charge Transport Through C-H···π Interactions

C-H···π interactions, a prevalent intermolecular force, play a pivotal role in chemistry, materials science, and life sciences. Despite extensive studies of their influence on intermolecular binding configurations and energetics, their impact on intermolecular coupling and charge transport remains unexplored. Here, we investigate the charge transport within supramolecular junctions connected by C-H···π and π-π interactions, respectively, and find that C-H···π interactions exhibit conductances that are 3.5 times those of π-π interactions. Angstrom-scale distance-dependent experiments indicate that the conductance of C-H···π supramolecular junctions experiences initial decay under stretching, followed by gradual convergence, in contrast with the periodic fluctuations in π-π stacked supramolecular junctions. Theoretical calculations show that charge transport within C-H···π interactions transitions from destructive to constructive quantum interference under stretching, with a larger range of constructive quantum interference compared with π-π stacking. This study establishes that C-H···π interactions facilitate efficient intermolecular charge transport and elucidates the evolution of quantum interference effects with assembly configuration, offering critical insights for the design of supramolecular materials and devices.