Tailoring the redox capabilities of organic ligands for metal-ligand coordination with vanadium single-sites

[摘要] The creation of single-site metal centers (SSMCs) through the formation of metal-organic coordination networks is an area of interest due to the proven ability of SSMCs to improve selectivity for heterogeneous catalysts. In order to better understand the reactivity potential for the SSMCs it is necessary to study the ligand-metal interaction in the metal-organic coordination networks. In the work reported here, we demonstrate the ability to tune the oxidation state of vanadium from II to IV through the tailoring of redox-active ligands. Using the Nheterocyclic ligands of bipyrimidine (BP), bispyrimidinyltetrazine (BMTZ), and biimidazole (BIM) complexed with metallic V, we have shown that the oxidation state of the V metal centers can be tuned to V(II) for BP, V(III) for BMTZ, and V(IV) for BIM. These redox-active ligands provide similar coordination environments when complexed into one dimensional chains but result in different oxidation states for the single-site metal center.

[发布日期] 2021-10-01

[关键词] Metal-organic coordination;On-surface redox assembly;Scanning tunneling microscopy;Density functional calculations;X-ray photoelectron spectroscopy;Redox-active ligands;Charge transfer;Metals