Cationic Thorium Alkyl Complexes of Rigid NON- and NNN-Donor Ligands: π-Arene Coordination as a Persistent Structural Motif

Reaction of the neutral dialkyl complex [(XA2)Th(CH2SiMe3)2] {1; XA2 = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene} with [CPh3][B(C6F5)4] in benzene or toluene at room temperature resulted in the formation of [(XA2)Th(CH2SiMe3)(η6-arene)][B(C6F5)4] {arene = C6H6 (5) and toluene (5B)}, which were characterized by 1H, 13C, and 2D NMR spectroscopy and by X-ray crystallography (for 5). In close analogy, reaction of …