Intramolecular London Dispersion Interactions in Single-Molecule Junctions.
J Am Chem Soc
; 146(7): 4716-4726, 2024 Feb 21.
Article
em En
| MEDLINE
| ID: mdl-38325000
ABSTRACT
This work shows the first example of using intramolecular London dispersion interactions to control molecular geometry and quantum transport in single-molecule junctions. Flexible σ-bonded molecular junctions typically occupy straight-chain geometries due to steric effects. Here, we synthesize a series of thiomethyl-terminated oligo(dimethylsilmethylene)s that bear [CH2-Si(CH3)2]n repeat units, where all backbone dihedral states are sterically equivalent. Scanning tunneling microscopy break-junction (STM-BJ) measurements and theoretical calculations indicate that in the absence of a strong steric bias concerted intramolecular London dispersion interactions staple the carbosilane backbone into coiled conformations that remain intact even as the junction is stretched to its breakpoint. As these kinked conformations are highly resistive to electronic transport, we observe record-high conductance decay values on an experimental junction length basis (ß = 1.86 ± 0.12 Å-1). These studies reveal the potential of using intramolecular London dispersion interactions to design single-molecule electronics.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2024
Tipo de documento:
Article