Synthesis and characterization of a tetraruthenium butterfly cluster containing a quadruply-bridging ligand derived from an N, N′-dipyrid-2-ylurea

Abstract

The tetraruthenium cluster complex [Ru 4(μ 4-κ 4-dmpu)(CO) 10], H 2dmpu = N, N′-bis(6-methylpyrid-2-yl)urea, has been prepared by treating [Ru 3(CO) 12] with H 2dmpu in toluene at reflux temperature. An X-ray diffraction study has determined that this cluster has a butterfly metallic skeleton hold up by a doubly-deprotonated N, N′-bis(6-methylpyrid-2-yl)urea ligand (dmpu). This ligand has the pyridine N atoms attached to the wing-tip Ru atoms and the amido N atoms spanning Ru–Ru wing-edges, in such a way that the cluster has C 2 symmetry. The donor atoms of doubly-deprotonated N, N′-dipyrid-2-ylureas seem to be appropriately arranged to hold butterfly tetranuclear clusters.