New homoleptic anionic aryloxolanthanide(III) complexes with unusual coordination trapping of the alkali-metal counter ions

Abstract

The complex {Cs₂[La(OAr)₅]}(Ar = C₆H₃Prⁱ₂-2,6), from LaCl₃ or La₂(OAr)₆ and CsOAr in tetrahydrofuran, has an unprecedented polymeric structure in which five-coordinate [La(OAr)₅]^2– anions are bonded to caesium in a three- dimensional network solely by Ar–Cs π bonds, whilst {Na[Nd(Odpp)₄]}(dpp = C₆H₃Ph₂-2,6), from NdCl₃ and NaOdpp in 1,3,5-tri-tert-butylbenzene at 300 °C, has an unexpected monomeric structure with sodium bonded to three oxygens and encapsulated by three phenyl groups of [Nd(Odpp)₄]^–.