Esser Research Group (@besserchemistry.bsky.social)

Discover the hidden potential of the antiaromatic [4]cyclodibenzopentalene for tomorrow's electronics. It enables two stable conduction pathways, unlocking new possibilities in molecular-scale switching. Compared to conventional [10]CPP, it shows remarkable versatility. pubs.acs.org/doi/10.1021/...

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Dual-State Ambipolar Charge Transport in Antiaromatic [4]cyclodibenzopentalene Single-Molecule Nanohoops Antiaromatic compounds are of great interest due to their narrow highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps, high reactivity, and enhanced charge mobility, yet their role in single-molecule electronics is still not well understood. Using electrochemically controlled scanning tunneling microscopy break junction (ECSTM-BJ) measurements, we compared the energy-alignment-dependent conductance of the aromatic [10]cycloparaphenylene ([10]CPP) and the antiaromatic [4]cyclodibenzopentalene ([4]CDBP). While [10]CPP showed a single conductance state via the HOMO, [4]CDBP exhibited two distinct states involving both the HOMO and LUMO. Our analysis and DFT calculations attribute this dual-state behavior to unique anchoring mode and energy-level realignment within a narrow HOMO-LUMO gap. This property enables electron- and hole-dominated pathways that depend on the anchoring configuration and coexist at a fixed gate potential. This phenomenon, also observed in the [4]CDBP⊃C60 structure, highlights the potential of antiaromatic molecules for advanced molecular electronics. https://pubs.acs.org/doi/10.1021/jacs.4c17115