Dimethyl Sulfate Induced Nucleophilic Substitution of the [Bis(1,2-dicarbollido)-3-cobalt(1-)]ate Ion. Syntheses, Properties and Structures of Its 8,8'-μ-Sulfato, 8-Phenyland 8-Dioxane Derivatives

Syntheses and structures of [8,8'-μ-(OSO 2 O)(1,2-C 2 B 9 H 10 ) 2 -3-Co] - and [(8-Ph-1,2-C 2 B 9 H 10 )-3-Co-(1',2'-C 2 B 9 H 11 ] - ions and of [(8-dioxane-1,2-C 2 B 9 H 10 )-3-Co-(1',2'-C 2 B 9 H 11 )] zwitterion are described. All compounds result on dimethyl sulfate induced nucleophilic B-substitution of the parent cobalta-carborane sandwich ion under acid catalysis. A general mechanism is proposed. Constitutions of all compounds are inferred from the mass and multinuclear NMR spectroscopy and all structures are established by X-ray diffraction. Selected NMR and X-ray data are presented.