Details

Autor(en) / Beteiligte

• Wright, Demelza
• Sangtarash, Sara
• Mueller, Niclas S.
• Lin, Qianqi
• Sadeghi, Hatef
• Baumberg, Jeremy J.

Titel

Vibrational Stark Effects: Ionic Influence on Local Fields

Ist Teil von

• The journal of physical chemistry letters, 2022-06, Vol.13 (22), p.4905-4911

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Molecules containing vibrational Stark shift reporters provide a useful tool for measuring DC electric fields in situ. To quantify this effect theoretically, density functional theory (DFT) calculations are usually utilized in a uniform electric field. However, using a combined theoretical and experimental study, we demonstrate here that uniform field DFT cannot simultaneously model the behavior of the three strongest vibrational modes in molecules forming a monolayer on an electrode. We show, by directly modeling ionic movement, that the measured Stark shifts are explained by partial electrical double-layer penetration into the molecular layer. This effect is sensitive to the local environment, and the Stark shifts can be fully suppressed experimentally by introducing a mixed molecular layer that prevents ionic double-layer penetration.