Observation and manipulation of tris(dibenzoylmethanato)ruthenium molecules by low temperature scanning tunnelling microscopy

Abstract

The behaviour of tris(dibenzoylmethanato)ruthenium molecules has been studied using low temperature scanning tunneling microscopy after adsorption on Ag(111) and Cu(111). On both surfaces, the molecules present two adsorption geometries : a bi-lobed and a chiral threefold structure. This latter form can stand up to adopt a bi-lobed conformation which is oriented along the dense crystallographic directions. The molecular geometries after adsorption can be modified using the STM tip. In one of these modifications, a switch between two different conformations has been observed. The data recorded during the experiments show that this phenomenon is induced by the electric field in the STM junction.

Unraveling the molecular conformations of a single ruthenium complex adsorbed on the Ag(111) surface by calculations

“…The second structure is a bi-lobed structure, called the B geometry. Actually, as observed experimentally, 35 80% of the molecules present a bi-lobed shape on the surface after evaporation of Ru(dbm) 3 on Ag(111).…”

“…The adsorption energy including the van der Waals interaction between the molecule and the metallic surface reaches 0.34 eV. The corresponding STM images of a Ru(dbm) 3 molecule calculated with ESQC with parameters (bias voltage and tunneling current threshold for constant-current imaging mode) similar to those used in experiments 35 show a three-lobe structure (Fig. 3).…”

“…3 are qualitatively consistent with the experimental results and quantitatively reflect the main features presented in ref. 35 demonstrating the chirality of the molecule with its enantiomers on the substrate.…”

“…These stimuli can be light or local electric fields, which are enhanced beneath the tip, tunneling electrons, or a mechanical action provided by the tip. [29][30][31][32][33] In this work, we describe with numerical methods the adsorption and switching of the tris(dibenzoylmethanato)ruthenium (Ru(dbm) 3 ) molecule on the Ag(111) surface; 34,35 this molecule is of particular interest in the route towards the synthesis of larger entities devoted to charge transfer and logic gates. [36][37][38][39] Such a molecule with a Ru core can be considered as a precursor of a mixedvalence complex that is interesting for specific electronic properties through charge transfer generating different oxidation states.…”

“…These overall numerical results are in very good agreement with experimental results. 35 Unraveling the molecular conformations of a single ruthenium complex adsorbed on the Ag(111) surface by calculations Youness Benjalal, a Jacques Bonvoisin b and Xavier Bouju * b…”