Interpreting tunneling spectroscopic maps of a dinuclear Co(II) complex on gold

TL;DR

This study combines scanning tunneling microscopy and density functional theory to analyze a dinuclear Co(II) complex on gold, revealing substrate-induced geometric changes while electronic states remain similar to gas-phase molecules.

Contribution

It demonstrates how substrate interactions affect molecular geometry and electronic states, providing insights into interpreting tunneling spectroscopic maps.

Findings

Substrate interaction significantly alters molecular geometry.

Electronic states are largely preserved despite geometric changes.

Calculated maps match experimental contrasts, highlighting geometric and electronic influences.

Abstract

Scanning tunneling microscope data from a dinuclear Co(II) complex adsorbed on Au(111) are analysed using density functional theory calculations. We find that the interaction with the substrate substantially changes the geometry of the non-planar molecule. Its electronic states, however, remain fairly similar to those calculated for a gas-phase molecule. The calculations reproduce intriguing contrasts observed in experimental maps of the differential conductance dI/dV and reveal the relative importance of geometric and electronic factors that impinge on the image contrasts. For a meaningful comparison, it is important that the calculations closely mimic the experimental mode of measurement.