The Role of Neutral Coligands on the Stabilization of Mono-TpiPr2 U(III) Complexes

Autor: Isabel Santos, Adelino M. Galvão, Leonor Maria, José R. Ascenso, Angela Domingos
Rok vydání: 2004
Předmět:
Zdroj: Inorganic Chemistry. 43:6426-6434
ISSN: 1520-510X
0020-1669
Popis: The reaction of [UI(3)(THF)(4)] with 1 equiv of KTp()i(Pr)()2 in toluene in the presence of several neutral coligands allowed the synthesis of a novel family of mono-Tp()i(Pr)()2 complexes, [UI(2)Tp()i(Pr)()2(L)(x)()] [L = OPPh(3), x = 1 (3); L = C(5)H(5)N, x = 2 (4); L = Hpz()t(Bu,Me), x = 2 (5); and L = bipy, x = 1 (6)]. The adduct with THF, [UI(2)Tp()i(Pr)()2(THF)(2)(-)(3)] (1), could also be isolated by reacting [UI(3)(THF)(4)] with 1 equiv of KTp()i(Pr)()2 in tetrahydrofuran. However, complex 1 is not a good starting material to enter into the mono-Tp()i(Pr)()2 U(III) complexes as it decomposes in solution, leading to mixtures of U(III) species coordinated with Hpz()i(Pr)()2. The solid-state structures of 3, 4, and 6 were determined by single-crystal X-ray diffraction and revealed that this family of mono-Tp()i(Pr)()2 complexes can be six- (3) or seven-coordinated (4 and 6), depending on the nature of the neutral coligand. Complex 3 displays distorted octahedral coordination geometry, while 4 and 6 display distorted pentagonal bipyramid and capped octahedral geometries, respectively. Complexes 3 and 6 are static in solution, and the patterns of the (1)H NMR spectra are consistent with the C(s)() symmetry found in the solid state. The other complexes (1, 4, and 5) are fluxional, but the dynamic processes involved can be slowed by decreasing the temperature.
Databáze: OpenAIRE