Synthesis and characterization of imidocubanes with exocube GeIV and SnIV substituents:: [M(μ3-NGeMe3)]4 (M = Sn, Ge, Pb);: [Sn(μ3-NSnMe3)]4

The heteroleptic lithium amide, [(Me3Sn)(Me3Ge)NLi.(Et2O)](2) (2), reacts with MCl2 (M = Sn, Ge, Pb) to yield the corresponding cubane complexes [M(mu(3)-NGeMe3)](4) [M = Sn (3), Ge (4), Pb (5)]. In an analogous reaction with SnCl2, the lithium stannylamide, [(Me3Sn)(2)NLi.(Et2O)](2) (1), produces the mixed-valent Sn congener [Sn(mu(3)-NSnMe3)](4) (6). All imidocubanes contain both di- and tetravalent group 14 metals that are bridged by N. These structures are comprised of M4N4 (M = Sn, Pb, Ge) cores that possess varying distortion from perfect cube geometry. The Pb derivative (5) exhibits enhanced volatility and vapor-phase integrity.