Low-symmetry distortions in Extended Metal Atom Chains (EMACs): Origins and consequences for electron transport

The extended metal atoms chains (EMACs) constitute a diverse group of molecules differing in both length and identity of the constituent metal ions. They therefore present important challenges to our understanding of metal–metal bonding and its relationship to structural, magnetic and electron transport properties. In this review we summarise our current understanding of the origins of low-symmetry distortions in these chains and their impact on current flow through the molecule. We conclude that structure, magnetochemistry and resistance are all intimately related through a shared dependence on the energies and orientations of the frontier orbitals.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (293 K)Download as PowerPoint slideHighlights► Electron transport is controlled by the properties of the frontier orbitals. ► Structural distortions are driven by second-order mixing of frontier orbitals. ► Stretching in Cr3 chains enhances conductance. ► Bending in Ru3 chains enhances conductance through a change in spin state. ► The dominant channel has π symmetry in Ru3 chains but σ symmetry in Cr/Co.