Conductance and configuration of molecular gold-water-gold junctions under electric fields.

Journal Article (Journal Article)

Water molecules can mediate charge transfer in biological and chemical reactions by forming electronic coupling pathways. Understanding the mechanism requires a molecular-level electrical characterization of water. Here, we describe the measurement of single water molecular conductance at room temperature, characterize the structure of water molecules using infrared spectroscopy, and perform theoretical studies to assist in the interpretation of the experimental data. The study reveals two distinct states of water, corresponding to a parallel and perpendicular orientation of the molecules. Water molecules switch from parallel to perpendicular orientations on applying an electric field, producing switching from high to low conductance states, thus enabling the determination of single water molecular dipole moments. The work further shows that water-water interactions affect the atomic scale configuration and conductance of water molecules. These findings demonstrate the importance of the discrete nature of water molecules in electron transfer and set limits on water-mediated electron transfer rates.

Full Text

Duke Authors

Cited Authors

  • Xiang, L; Zhang, P; Liu, C; He, X; Li, HB; Li, Y; Wang, Z; Hihath, J; Kim, SH; Beratan, DN; Tao, N

Published Date

  • July 2020

Published In

Volume / Issue

  • 3 / 1

Start / End Page

  • 166 - 179

PubMed ID

  • 33103114

Pubmed Central ID

  • PMC7584381

Electronic International Standard Serial Number (EISSN)

  • 2590-2385

International Standard Serial Number (ISSN)

  • 2590-2393

Digital Object Identifier (DOI)

  • 10.1016/j.matt.2020.03.023


  • eng