Near i.r. transition of the µ-quinoxaline-bis(penta-ammineruthenium)(5+) ion

Abstract

Although the π* system of the bridging ligand in the µ-quinoxaline-bis(penta-ammineruthenium)(5+) ion (2) is considerably lower in energy than the π* system of the bridging ligand in the previously reported µ-pyrazine-bis(penta-ammineruthenium)(5+) ion (1), the near i.r. transition for (2)(ν_max 5900 cm^–1) occurs at essentially the same energy as that for (1)(ν_max 6300 cm^–1), a result suggestive of the mixed-valence Ru^II–Ru^III representation of the ion as opposed to a delocalized Ru^II½–Ru^II½ description.