Niobium complexes iodides

Reactions of Tantalum(V) and Niobium(V) Iodides with Pyridine. Both niobium(V) and tantalum(V) iodide were reduced in pyridine. In each case the di-adduct of pyridine with the metal tetraiodide was produced, along with elemental iodine as its pyridine complex. The two reduction products were identified by analysis after washing with chloroform to remove the iodine liberated in the reaction. Further identification of the tantalum product was provided by x-ray diffraction data, which compared favorably to those obtained for samples of the tetraiododi(pyridine)niobium (IV) as shown in Table V. 

Apparently the dissociation is enhanced in pyridine, owing to formation of the stable complexes of both niobium (IV) iodide and elemental iodine. Although some reduction of tantalum (V) iodide also occurred in pyridine, the analytical data suggest that this reaction was not complete, and that some unreduced tantalum (V) iodide remained in the washed product. By comparison with niobium (V) iodide, the smaller extent of reduction of tantalum (V) iodide may be accounted for in terms of the greater stability of the latter toward the dissociation shown in Equation 8. 

Cesium niobium iodide complexes, 46 34 Cesium pseudohalide complexes, 46 42 Cesium salt (CS2MCy, lattice energy, 22 22 Cesium tetraiodide, structure of, 3 152 Cesium trifluoroacetates, 17 8, 31, 32 CF, 33 110... 

Redox Chemistry of the Group 5 Clusters Ligand Substitution Electronic and Molecular Structure Niobium Iodide Clusters NbJJ"-Materials Chemistry Derived from Soluble Metal Halide Clusters A. Higher Nuclearity Clusters Supported Cluster Materials Charge-Transfer Salt Complexes Extended Solids Chemically Modified Surfaces... 

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