Metal bound azo anion radicals

Using azopyridine ligands (L) the first anion radical complexes of rutheniu m(II) have been synthesized using hydridic starting materials which supply both the metal and the reducing equivalent. Species incorporating Ru-II(L.- ), Ru-II(L.-), and Ru-II(L)(L.-) fragments have been isolated, the coligand s being PPh3, Cl-, CO and H-. Weak acids including water readily convert th e radicals to nonradical species. The X-ray structure, spectra, EHMO fronti er orbitals, magnetism and electrochemistry of the species have been scruti nized and correlated.