Coordination chemistry relies on harnessing active metal sites within organic matrices. Polynuclear complexes—where organic ligands bind to several metal atoms—are relevant due to their electronic/magnetic properties and potential for functional reactivity pathways. However, their synthesis remains challenging; few geometries and configurations have been achieved. Here, we synthesise—via supramolecular chemistry on a noble metal surface—one-dimensional metal-organic nanostructures composed of terpyridine (tpy)-based molecules coordinated with well-defined polynuclear iron clusters. Combining low-temperature scanning probe microscopy and density functional theory, we demonstrate that the coordination motif consists of coplanar tpyʼs linked via a quasi-linear tri-iron node in a mixed (positive-)valence metal–metal bond configuration. This unusual linkage is stabilised by local accumulation of electrons between cations, ligand and surface. The latter, enabled by bottom-up on-surface synthesis, yields an electronic structure that hints at a chemically active polynuclear metal centre, paving the way for nanomaterials with novel catalytic/magnetic functionalities.


C. Krull, M. Castelli, P. Hapala, D. Kumar, A. Tadich, M. Capsoni, M. T. Edmonds, J. Hellerstedt, S. A. Burke, P. Jelinek, A. Schiffrin 
Iron-based trinuclear metal-organic nanostructureson a surface with local charge accumulation 
Nat. Commun. 9 (2018) 3211(1) - 3211(7).


The manuscript was highlighted in Nature Research Chemistry Community blog: Click here.