Synthesis and properties of a germanium(II) metalloheterocycle derived from 1,8-di(isopropylamino)naphthalene.: A novel ligand leading to formation of Ni{Ge[(iPrN)2C10H6]}4

A novel mononuclear germylene, Ge[1,8-((PrN)-Pr-i)(2)C10H6] (1), was isolated as a stable crystalline solid by the reaction of Li-2[1,8-((PrN)-Pr-i)(2)C10H6] with GeCl2(1,4-dioxane). Structural examination of I shows that this compound possesses a planar six-membered heterocyclic ring system with a Ge(II) center and that the steric impact of the substituents on the nitrogen centers is greater than that for the related five-membered metalloheterocycles. Compound 1 is readily oxidized with elemental S and Se and the structural details for the dinuclear product [[1,8-((PrN)-Pr-i)(2)C10H6]Ge(mu -S)](2) are reported. Furthermore, the lone pair of electrons on the Ge(II) center in I allows this species to function as a novel ligand for the preparation of the unique tetrakis(germylene) complex Ni{Ge[((PrN)-Pr-i)(2)C10H6]}(4) (4). The structural features of 4 are reported and show that the germylene ligand, when coordinated to the Ni(O) center, now exhibited a twisted (nonplanar) heterometallocycle and a cone angle of 145 degrees.