Metal Allyl Complexes with Bulky Ligands: Stabilization of Homoleptic Thorium Compounds, [(SiMe3)nC3H5-n]4Th (n = 1, 2)
datasetposted on 01.09.2004, 00:00 by Christin N. Carlson, Timothy P. Hanusa, William W. Brennessel
Unlike the parent (C3H5)4Th that decomposes at 0 °C, homoleptic tetra(allyl)thorium complexes [(SiMe3)nC3H5-n]4Th (n = 1, 2) have been prepared from ThBr4(thf)4 and K[(SiMe3)nC3H5-n] that are stable up to 90 °C (n = 1) or 124 °C (n = 2). The molecules, which are fluxional on the NMR time scale, contain the first structurally authenticated Th−allyl bonds. The trimethylsilyl groups cause relatively little perturbation in the core metal−allyl geometry but markedly increase the kinetic stability of the compounds.