Hydrocarbon-soluble, polymetallic, lanthanoid aryloxides constructed utilising ligands with distal But groups

The lanthanoid(III) aryloxide complexes [La(OAr)3(thf)3]2·5thf (1), [Nd3(OAr)9(thf)4]·4thf (2), [Ln(OAr)3(thf)2]2·2thf [Ln = Er (3); Yb (4)], [Ln(OAr)3]n [Ln = Eu (5); Yb (6)], [La4(OAr)12(OH2)] (7) and [Nd3(OAr)9(HOAr)2(thf)]·HOAr (8) (Ar = C6H3But2-3,5) have been isolated from direct reactions of elemental lanthanoids and HOAr under high temperature conditions followed by crystallisation from thf or hexane. A key feature of these materials is the formation of hydrocarbon-soluble, polynuclear complexes, as established by X-ray crystallography, even in the presence of a strong donor (thf), as a consequence of the geometric properties of HOAr, which has minimal steric bulk near the ligating oxygen atom, allowing higher coordination numbers, but with hydrophobic But groups on the periphery conferring excellent solubility.