Article Title

Steric and electronic selectivity in the synthesis of Fe-1,2,4,5-tetracyanobenzene (TCNB) complexes on Au(111): From topological confinement to bond formation

Authors

Shawulienu Kezilebieke, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS UMR 7504, Université de Strasbourg, F-67034 Strasbourg, France
Anis Amokrane, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS UMR 7504, Université de Strasbourg, F-67034 Strasbourg, France
Mauro Boero, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS UMR 7504, Université de Strasbourg, F-67034 Strasbourg, France
Sylvain Clair, Université Aix-Marseille, IM2NP, CNRS UMR 7334, Campus de Saint-Jérme, Case 142, F-13397 Marseille Cedex 20, France
Mathieu Abel, Université Aix-Marseille, IM2NP, CNRS UMR 7334, Campus de Saint-Jérme, Case 142, F-13397 Marseille Cedex 20, France
Jean-Pierre Bucher, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS UMR 7504, Université de Strasbourg, F-67034 Strasbourg, France

Keywords

scanning tunneling spectroscopy, STM, self-assembly, steric hindrance, metal-organic coordination, chirality, nanochemistry, surface state

Abstract

A study of the surface assisted self-assembly of 1,2,4,5-tetracyanobenzene (TCNB) acceptor molecules and Fe atoms on an Au(111) surface is presented. While conditions to get the two-dimensional arrays of stable Fe(TCNB)4 complexes are clearly identified, ultrahigh vacuum scanning tunneling microscopy and spectroscopy (STM/STS) coupled with first-principles calculations reveals that situations may occur where Fe and TCNB survive on the surface (as Fe–4TCNB entities) at a higher density than the original molecular monolayer without forming coordination bonds with each other. It is found that the square planar coordination of the Fe(TCNB)4 monomer complexes cannot fully develop in the presence of lateral strain due to growth-induced confinement. A phenomenon similar to steric hindrance involving a strongly modified chirality with a Fe–N–C bond angle of 120° compared to the 180° for the stable complex may then explain why the Fe atom keeps its metallic bond with the surface. The competition between steric and electronic effects, not reported before, may arise elsewhere in surface chemistry involved in the synthesis of new and potentially useful organic nanomaterials.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-014-0450-y

Publisher

Tsinghua University Press

Recommended Citation

Shawulienu Kezilebieke,Anis Amokrane,Mauro Boero,Sylvain Clair,Mathieu Abel,Jean-Pierre Bucher, Steric and electronic selectivity in the synthesis of Fe-1,2,4,5-tetracyanobenzene (TCNB) complexes on Au(111): From topological confinement to bond formation. NanoRes.2014, 7(6): 888–897