Activation of Aryl Germanium(II) Chlorides by [Mo(PMe3)6] and [W(2-CH2PMe2)H(PMe3)4]: A New Route to Metal-Germanium Triple Bonds

摘要

Homoleptic trimethylphosphane complexes of transition metals, such as [Mo(PMe3)6] (2-Mo)[1] and [W(PMe3)6] (2-W),[2] form a class of rare and very reactive compounds.[3]-[5] The high reactivity of these complexes originates from the combination of strong -donor and weak -acceptor properties of the PMe3 ligand, which leads to very electron-rich metal centers[6] that are capable of activating bonds. A consequence of the high reactivity of the metal centers and the steric pressure caused by the PMe3 ligands in the complexes [M(PMe3)6] (M=Mo, W) is the facile dissociation of one PMe3 ligand to afford, through an intramolecular CH bond activation, the cyclometalated products [M(2-CH2PMe2)H(PMe3)4].[1], [2] The complexes [M(PMe3)6] and their cyclometalation products are subject to various ligand displacement and oxidative addition reactions.[7] We report here a new reaction type of these electron-rich metal complexes that involves a GeCl bond heterolysis of an aryl germanium(II) chloride to form metal-germanium triple bonds.