Selenium-based self-assembled monolayers: the nature of adsorbate-surface interactions.

Area of Science:

• Surface science
• Materials science
• Computational chemistry

Background:

• Self-assembled monolayers (SAMs) of selenols on gold surfaces are of interest for their electronic properties.
• Experimental studies on the Se-Au interface stability and conductance yield contradictory results.
• Theoretical studies have primarily focused on electron transport, neglecting structural and thermodynamic aspects.

Purpose of the Study:

• To investigate the binding of selenols to the Au(111) surface.
• To provide theoretical insights into the geometry, stability, and electronic properties of selenol SAMs.
• To propose a factor explaining conflicting experimental observations.

Main Methods:

• Density functional theory (DFT) calculations.
• Plane wave basis sets and periodic boundary conditions.
• Analysis of headgroup geometry, monolayer stability, and electronic properties.

Main Results:

• Detailed examination of selenol binding to Au(111).
• Insights into the structural and electronic characteristics of selenol SAMs.
• Proposal that conjugated backbones enhance intramolecular electron transport in selenols.

Conclusions:

• The binding and stability of selenol SAMs on Au(111) are theoretically characterized.
• Conjugated backbones are proposed as a key factor for enhanced intramolecular electron transport in selenols.
• This finding may reconcile conflicting experimental data regarding Se-Au interface conductance.