Synthesis and characterization of uranium(III) compounds supported by the hydrotris(3,5-dimethyl-pyrazolyl)borate ligand: Crystal structures of [U(Tp(Me2))(2)(X)] complexes (X = OC6H2-2,4,6-Me-3, dmpz, Cl)

摘要

Reaction of [U(Tp(Mc2))(2)(NR2)] (R = Ph SiMe3) with protic substrates such as 2,4,6-trimethyl phenol (HOC6H2-2,4,6-Me-3), 3,5-dimethylpyrazole (Hdmpz), 2-mercaptopyridine (HSC5H4N) and phenylacetylene (HCCPh) afforded the corresponding [U(Tp(Me2))(2)(OAr)] (Ar = C6H2-2,4,6-Me-3) (1), [U(Tp(Me2))(2)(dmpz)] (2), [U(Tp(Me2))(2)(eta(2)-SC5H4N)] (3), and [U(Tp(Me2))(2)(CCPh)] (4) compounds. Reaction of [U(Tp(Me2))(2)(NR2)] with Me3SnCl or Me3SiBr gave [U(Tp(Me2))(2)Cl] (5) and [U(Tp(Me2))(2)Br] (6), respectively, in high yield. The amido precursors failed to react with cyclopentadiene, but metathesis of [U(Tp(Me2))(2)I] with NaCp yielded [U(kappa(3)-Tp(Me2))(kappa(2)-Tp(Me2))(eta(5)-Cp)] (7). Thermolysis of 7 resulted in oxidation of the metal centre and redistribution of the ligands, giving [UCP3(dmpz)] (8). pyrazabole (9) and [U(Tp(Me2))(dmpz)(3)] (10). The complexes have been fully characterized by spectroscopic methods and the structures of 1, 2, and 5 were confirmed by X-ray crystallographic studies. In the solid state the complexes exhibit distorted pentagonal bipyramidal geometries. (c) 2005 Elsevier Ltd. All rights reserved.