Extremely Stable Thorium(IV) Dialkyl Complexes Supported by Rigid Tridentate 4,5-Bis(anilido)xanthene and 2,6-Bis(anilidomethyl)pyridine Ligands

A new NON-donor ligand, 4,5-bis(2,6-diisopropylanilino)-2,7-di-tert-butyl-9,9-dimethylxanthene (H2[XA2], 1), was prepared by palladium-catalyzed coupling of 2,6-diisopropylaniline with the appropriate dibromoxanthene precursor. Stable K2(dme)2[XA2] (2) and Na2[XA2] (3) salts were accessible by deprotonation of H2[XA2] with KH in dme or NaH in toluene. The thermally unstable lithium salt of McConville's …