Synthesis of an Electron Pooling Ligand Based on Triruthenium Clusters and Electrochemical Reduction of CO2 by Its Zinc(II) Complex

An electron pooling complexed ligand (PL) was prepared by linking (mu)3-oxo Ru3 clusters with 1,4,7-tris(4-pyridylmethyl)-1,4,7triazacyclononane (pic3tacn). The cyclic voltammogram of the pooling ligand appeared similar to the Ru3 cluster monomers. Each wave corresponded to three simultaneous 1e- processes. In the presence of Zn(II) ions, CO2 was reduced, indicating cooperation between the Ru3 cluster centers. IR spectroelectrochemistry (IRSEC) indicated that the products of reduction were carbonate and formate and CO.