Cyclophane-based shielding strategy for singly dispersed graphene nanoribbons

Structurally precise graphene nanoribbons (GNRs) hold great promise for nanoelectronic devices owing to their tunable bandgaps and unique electronic properties. However, their practical integration into single-ribbon devices remains impeded by strong inter-ribbon aggregation. Here we introduce a cyclophane-based shielding strategy that not only sterically protects the GNR backbone but also imparts internal strain, enabling singly dispersed GNRs while simultaneously modulating their optoelectronic properties, as demonstrated by the synthesis and investigation of three cyclophane-shielded GNRs 1a-c and model nanographenes with varying cyclic chain lengths. Terahertz spectroscopy reveals a marked increase in short-range charge carrier mobility-from 190 to 330 cm²V^-1s^-1 -as the chain length shortens, attributed to both reduced effective mass and increased scattering time. The resulting singly dispersed cyclophane-shielded GNRs enable the fabrication of single-electron transistors showing a clear Coulomb blockade behaviour at low temperatures. This work provides a generalizable strategy for engineering solution-processable GNRs compatible with quantum device applications.