Solvatothermal Syntheses and Structural Characterizations of Polyoxoalkoxometalates: The Heptanuclear [{Fe(OH)(CH₃CN)₂} Fe₆OCl₆ {(OCH₂)₃CCH₂OH}₄], the Decanuclear [Fe₁₀O₂Cl₈{(OCH₂) ₃CCH₂CH₃}₆], and the Bimetallic

Solvatothermal syntheses have been exploited to effect the isolation of three novel polyoxoalkoxometalate clusters, [{Fe(OH)(CH₃CN)₂} Fe₆OCl₆{(OCH₂)₃ CCH₂OH}₄] (1), [Fe₁₀O₂Cl₈{(OCH₂) ₃CCH₂CH₃}₆] (2), and [(VO)₂Fe₈O₂ Cl₆{(OCH₂)₃CCH₂CH₃} ₆] (3). The structure of 1 may be described as a hexametalate core {Fe₆OCl₆}¹⁰⁺, consisting of a octahedral arrangement of chloride ligands encasing an octahedron of six Fe(III) sites, with a central oxo group. The remaining four coordination sites at each octahedral iron center are occupied by doubly bridging oxygen donors from the trisalkoxo ligands. One triangular face of this substructure, defined by three oxygen atoms, from three adjacent trisalkoxo ligands, is capped by the {Fe(OH)(CH₃CN)₂}²⁺ subunit. The structure of 2 is based on the decametalate core of edge-sharing octahedra. The eight peripheral Fe(III) sites of the cluster bond to four oxygen donors from the trisalkoxo ligands, a terminal Cl^- ligand, and one of the μ⁶-oxo groups. The two central iron sites are linked to four oxygen donors from the trisalkoxo ligands and to both of the μ⁶-oxo groups. Cluster 3 is structurally related to 2 with two {FeCl}²⁺ units replaced by {VO}²⁺ groups.