ZERO OXIDATION-STATE COMPOUNDS OF SCANDIUM, YTTRIUM, AND THE LANTHANIDES

The first stable zero oxidation state complexes of Sc, Y, and the lanthanides have been prepared by metal vapour synthesis. Whilst the tris-diimine complexes [M(Bu(t)-DAB)3] are formally M0 compounds, structural and spectroscopic data indicate that they are best regarded as M3+ salts of the Bu(t)-DAB radical anion. The sandwich compounds [M(eta-C6H3BU(t)3)2], however, have been shown to be genuine f-element (0) complexes from detailed magnetic and structural studies. The bonding in these complexes and some of their reaction chemistry is also discussed.