Synthesis, Structure, and Reactivity of Zwitterionic Divalent Rare-Earth Metal Silanides

The synthesis and structures of the first zwitterionic divalent rare-earth metal silanides of the formula [Si­(SiMe2OMe)3-κ3]2M (M-3), where M = Eu, Yb, and Sm, are reported. M-3 compounds feature spirocyclic bicyclooctane structures in which the central rare-earth metal ions are being octahedrally coordinated by six methoxy groups. The reaction of Yb-3 with BPh3 and W­(CO)6 respectively generated the trinuclear zwitterions [Ph3BSi­(SiMe2OMe)3-κ3]2Yb (Yb-4) and [(CO)5WSi­(SiMe2OMe)3-κ3]2Yb (Yb-5) in good yield.