Molecular Mechanochemistry Understood at the Nanoscale: Thiolate Interfaces and Junctions with Copper Surfaces and Clusters

Abstract

Two very different approaches to activate chemical bonds, nanoscale mechanochemistry and the ubiquitous thermochemistry, are studied and compared for a range of different thiolate/copper interfaces and junctions using self-assembled monolayers (SAMs) on perfect surfaces as well as single molecules anchored at steps and on clusters. In nanoscale mechanochemistry the activation proceeds by supplying locally pure mechanical energy to the desired atom(s) and/or bond(s). Using both dynamic and static electronic structure methods we predict vastly different reaction pathways and product classes for the two types of activation. These differences can be understood in terms of directional mechanical manipulation of coordination numbers and system fluctuations in the process of mechanical activation which affect the coupling of the thiolate molecular orbitals to the metal part of the molecule/metal junction or interface. The observed conceptual differences are huge in size and general in nature.

Mechanochemistry in Cu nanowires: N andN2enhancing the atomic chain formation

“…Since copper NWs became a promising possibility as nanocontacts and motivated by the recent works about the interaction between thiolates with copper clusters or surfaces 27,28 or by the interesting results obtained from gold NWs doped with light impurities, one investigation about the mechanochemistry of light impurities in copper NWs is demanded. In this work, we study theoretically the behavior of copper NWs doped with H, B, C, N, O, S, and N 2 impurities under stretching conditions until their rupture, observing their mechanical and electronic structure properties.…”

Self-Assembled Oligomeric Structures from 1,4-Benzenedithiol on Au(111) and the Formation of Conductive Linkers between Gold Nanoparticles

“…Indeed, pulling experiments for thiolates on gold also suggest that gold atoms can be pulled out of the surface by this process. 113 …”

Mechanical Control of Nanomaterials and Nanosystems

“…Simulations of mechanical strength of chemical bonds have been made in other systems. For example, mechanical properties of C‐S bonding within self‐assembled monolayer (SAM) on Cu(111) surface and chemical bonds sandwiched between Cu nanowires have recently been reported 19…”