Hexanuclear Niobium Cluster Complex Anions with Acetato Ligands on Intramolecular Bridging Sites: [Nb6Cli4(OAc)i8Cla6]2– and [Nb6(OAc)i12Cla6]2–

From the reaction of [Nb6Cl14(H2O)4]·4H2O with acetic anhydride in the presence of an excess of (nBu4N)F the novel cluster compounds (nBu4N)2[Nb6Cli4(OAc)i8Cla6] (1) and (nBu4N)2[Nb6(OAc)i12Cla6] (2) (OAc = acetato ligand) are obtained. They are the first examples of hexanuclear niobium cluster compounds with acetato ligands on the inner sites of the metal atom octahedron. The crucial role of the presence of fluoride ions in the synthesis is discussed. Each acetato ligand bridges in a μ2‐η1‐fashion with one O atom an edge of the metal atom octahedron. The monoclinic crystals of 1 consist of discrete (nBu4N)+ cations and [Nb6Cli4(OAc)i8Cla6]2– cluster anions. They are oxidized by two electrons with respect to the cluster starting material. Besides the syntheses of 1 and 2, the structure of 1 and spectral properties of both compounds are reported. [ABSTRACT FROM AUTHOR]