Bis(permethylindenyl) complexes of thorium: Synthesis, structure, and reactivity

A variety of thorium complexes incorporating the bulky permethylindenyl lig and (Ind* = C9Me7) have been synthesized and characterized. Specifically, t he dichloride Ind*2ThCl2 is obtained by reaction of ThCl4 with Ind*Li, from which Ind*2ThMe2, Ind*Th-2(NMe2)(2), Ind*(2)-Th(NC4H4)(2), and Ind*Th-2(et a (3)-H3BH)(2) may be obtained by metathesis with MeLi, LiNMe2, LiNC4H4, an d Ca(BH4)(2), respectively. In contrast to simple metathesis, reaction of I nd*(2)-ThCl2 with KN(SiMe3)(2) yields the metallacyde Ind*Th-2(eta (2)-CH2S iMe2NSiMe3). X-ray diffraction studies on Ind*2ThCl2, Ind*2ThCl(mu -Cl)(2)L i(tmeda), Ind*2ThMe2, Ind*Th-2(NMe2)(2), Ind*(2)-Th(eta (2)-CH2SiMe2NSiMe3) , and Ind*Th-2(eta (3)-H3BH)(2) indicate that the permethylindenyl ligands in these complexes exhibit a variety of conformations.