Metal bound azo anion radicals

Using azopyridinc ligands (L) the First anion radical complexes of ruthenium(ll) have been synthesized using hydridic starting materials which supply both the metal and the reducing equivalent. Species incorporating Ru"(L~), Ruʹʹ(L~)2 and Ru"(L)(L~) fragments have been isolated, the coligands being PPh3, Cl-, CO and H-. Weak acids including water readily convert the radicals to nonradical species. The X-ray structure, spectra, EHMO frontier orbitals, magnetism and electrochemistry of the species have been scrutinized and correlated.