Multi‐electron Reduction Capacity and Multiple Binding Pockets in Metal–Organic Redox Assembly at Surfaces

摘要: Metal-ligand complexation at surfaces utilizing redox-active ligands has been demonstrated to produce uniform single-site metals centers in regular coordination networks. Two key design considerations are the electron storage capacity of ligand and metal-coordinating pockets on ligand. In an effort move toward greater complexity systems, particularly dinuclear metal centers, we designed synthesized tetraethyltetra-aza-anthraquinone, TAAQ, which superior capabilities four ligating a diverging geometry. Cyclic voltammetry studies free demonstrate its ability undergo up four-electron reduction. Solution-based with analogous ligand, diethyldi-aza-anthraquinone, these redox molecular environment. Surface conducted Au(111) surface TAAQ's complex Fe. This can be observed different stoichiometric ratios Fe:TAAQ as Fe 2p core level shifts X-ray photoelectron spectroscopy. Scanning tunneling microscopy experiments confirmed formation metal-organic structures. The striking feature structures is their irregularity, indicates presence multiple local binding motifs. Density functional theory calculations confirm several energetically accessible isomers, accounts for non-uniformity chains.