Strongly reshaped organic-metal interfaces: Tetracyanoethylene on Cu(100)

TL;DR

This study combines experimental and theoretical methods to reveal that TCNE molecules strongly modify the Cu(100) surface structure through chemisorption and charge transfer, rather than forming a coordination network.

Contribution

It demonstrates that TCNE induces significant surface restructuring on Cu(100), providing new insights into organic-metal interface interactions.

Findings

Surface atoms become highly buckled upon TCNE adsorption

Chemisorption involves partial charge transfer from TCNE to Cu

Surface restructuring dominates over coordination network formation

Abstract

The interaction of the strong electron-acceptor tetracyanoethylene (TCNE) with the Cu(100) surface has been studied with scanning tunneling microscopy experiments and first-principles density functional theory calculations. We compare two different adsorption models with the experimental results and show that the molecular self-assembly is caused by a strong structural modification of the Cu(100) surface rather than the formation of a coordination network by diffusing Cu adatoms. Surface atoms become highly buckled and the chemisorption of TCNE is accompanied by a partial charge-transfer.