Manipulation of organoactinide coordinative unsaturation. Synthesis, structures, and reactivity of thorium hydrocarbyls and hydrides with chelating bis(tetramethylcyclopentadienyl) ancillary ligands

Abstract

In an effort to open the actinide coordination sphere while preserving the frontier orbitals and other advantages of Cp'/sub 2/An ancillary ligation, the authors have synthesized and explored the actinide coordination chemistry of the first chelating bis(permethylcyclopentadienyl) ligand (A, Me/sub 2/SiCp''/sub 2/). In this contribution, they present an account of thorium hydrocarbyl and hydride chemistry based upon this ligand. The discussion includes both ligand synthetic as well as organometallic synthetic and homogeneous catalytic details. It is seen that Me/sub 2/SiCp''/sub 2/Th ligation can effect substantial changes in molecular structure and catalytic reactivity over Cp'/sub 2/Th analogues. They discuss in detail the crystal structures of a mononuclear thorium bis(hydrocarbyl) and a dimeric thorium tetrahydride. The latter result features a very short Th-Th distance.