Single and double alkyl abstraction from a bis(anilido)xanthene thorium(IV) dibenzyl complex: Isolation of an organothorium cation and a thorium dication

摘要

Reaction of [(XA(2))ThCl2(dme)] [XA(2) = 4,5-bis(2,6diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene] with 2 equiv of PhCH2MgCl resulted in the formation of solvent-free [(XA(2))Th(CH2Ph)(2)] (1). Subsequent reaction of 1 with either 1 or 2 equiv of B(C6F5)(3) allowed isolation of the first non-cyclopentadienyl actinide alkyl cation, [(XA(2))Th(CH2Ph)][PhCH2B(C6F5)(3)] (2), and a rare example of an actinide dication, [(XA(2))Th][PhCH2B(C6F5)(3)](2) (3). The X-ray crystal structure of the dication reveals pi-coordination of both PhCH2B(C6F5)(3) anions, and solution NMR spectroscopy shows that a similar mode of contact ion pairing is operative in the monocation.