Synthesis of a new stable, neutral organothulium(II) complex by reduction of a thulium(III) precursor

The new stable, neutral Tm-II complex (Cp-ttt)(2)Tm [Cp-ttt = 1,2,4-tris(tert-butyl)cyclopentadienyl] can be obtained either by direct reaction of NaCpttt with TmI2 or by reduction of (Cp-ttt)(2)TmI in non-polar solvents; this latter route may prove itself useful for the isolation of other neutral non-classical low-valent organolanthanide species.