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Integrating multidisciplinary efforts from physics, chemistry, biology, and materials science, the field of single-molecule electronics has witnessed remarkable progress over the past two decades thanks to the development of single-molecule junction techniques. To date, researchers have interrogated charge transport across a broad spectrum of single molecules. While the electrical properties of covalently linked molecules have been extensively investigated, the impact of non-covalent interactions has only started to garner increasing attention in recent years. Undoubtedly, a deep understanding of both covalent and non-covalent interactions is imperative to expand the functionality and scalability of molecular-scale devices with the potential of using molecules as active components in various applications. In this review, we survey recent advances in probing how non-covalent interactions affect electron transmission through single molecules using single-molecule junction techniques. We concentrate on understanding the role of several key non-covalent interactions, including π–π and σ–σ stacking, hydrogen bonding, host–guest interactions, charge transfer complexation, and mechanically interlocked molecules. We aim to provide molecular-level insights into the structure–property relations of molecular junctions that feature these interactions from both experimental and theoretical perspectives.
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Proximity and single-molecule energetics
Probing single molecules in their nanoenvironment can reveal site-specific phenomena that would be obscured by ensemble-averaging experiments on macroscopic populations of molecules. Particularly in the past decade, major technological breakthroughs in scanning probe microscopy (SPM) have led to unprecedented spatial resolution and versatility and enabled the interrogation of molecular conformation, bond order, molecular orbitals, charge states, spins, phonons, and intermolecular interactions. On page 452 of this issue, Peng et al. ( 1 ) use SPM to directly measure the triplet lifetime of an individual pentacene molecule and demonstrate its dependence on interactions with nearby oxygen molecules with atomic precision. In addition to allowing the local tuning and probing of spin-spin interactions between molecules, this study represents a notable advance in the single-molecule regime and provides insights into many macroscopic behaviors and related applications in catalysis, energy-conversion materials, or biological systems.
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- Award ID(s):
- 1944796
- PAR ID:
- 10319991
- Date Published:
- Journal Name:
- Science
- Volume:
- 373
- Issue:
- 6553
- ISSN:
- 0036-8075
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1126/science.abj5860
