LIGAND-BRIDGED COMPLEXES OF RUTHENIUM(III) - MAGNETIC-PROPERTIES OF LIGAND-BRIDGED, DIMERIC AND PYRAZINE-BRIDGED, POLYMERIC COMPLEXES

A series of ligand-bridged complexes of ruthenium(III) have been prepared utilizing pyrazine, 4, 4'-bipyridine, and 1, 2-bis(4-pyridyl)ethane as the bridging ligands. The preparations involve the use of Ce(IV) to oxidize complexes of ruthenium(II) whose preparations were described previously. Dimeric complexes of the three bridging ligands, as well as trimeric and tetrameric pyrazine-bridged complexes, were prepared. The electronic spectra and magnetic properties of these formally low-spin d5 metal complexes were studied, the latter down to liquid-helium temperatures. The flexibility in the synthetic chemistry allowed, in principle, for a systematic study of the magnetic effects of different metal-metal interactions arising from changes in the bridging ligand and in polymer chain length. However, the magnetic results indicate little, if any, interactions in any of the complexes including the polymeric cases where the possibility of extended metal-metal interactions exists. © 1979, American Chemical Society. All rights reserved.