Charge gating and electronic delocalization over a denderimeric assembly of trinuclear ruthenium clusters

A zeroth-order dendrimer was formed using a tridentate bridging ligand, 2,4,6-tri-4-pyridyl-S-triazine, and the redox-active trinuclear ruthenium cluster Ru₃O(OAc)₆(CO)(py)(H₂O). The electronic properties of this dendrimer were probed using cyclic voltammetry. IR spectroelectrochemistry was performed at both low (-30°C) and room temperature. The IR spectroelectrochemical response at -30°C was straightforward, but at room temperature, the dendrimer exhibits an unusual and complex series of electronic behaviors, including intramolecular cluster-to-bridging-ligand charge transfer, gated electron transfer, and dynamic exchange on the IR time scale.