Abstract |
Reactions of UI3(THF)(4), UCl4 and ThCl4 with 1 equiv. of tris(3,5-dimethylpyrazolyl)methane (Tpm*) in THF led to the formation of the complexes [U(Tpm*)I-3(THF)] (1), [U(Tpm*)Cl-4] (2) and [Th(Tpm*)Cl-4] (3) in good yields. The NMR spectra indicated symmetrical structures in solution, with equivalent pyrazolyl groups of the Tpm* ligand. The X-ray crystal structures of the three complexes were determined and in all cases the metallic centre is seven-coordinated, presenting distorted capped octahedral coordination geometry with near C-3v symmetry. In 1, the tridentate pyrazolylmethane ligand and the three iodine atoms define the two staggered triangular faces of the octahedron, respectively, and the latter is capped by the THF oxygen. In 2 and 3, the coordination geometry is similar, with three chlorine atoms defining a triangular face capped by the fourth chlorine. (C) 2011 Elsevier B.V. All rights reserved. |