Synthesis and Structures of Scandium and Lutetium Benzyl Complexes

Scandium and lutetium benzyl complexes were prepared. Reaction of [ScCl3(THF)3] with potassium benzyl afforded [Sc(CH2Ph)3(THF)3] (1). In the solid state the coordination polyhedron is a distorted octahedron, in which the benzyl groups are located in a facial arrangement on one side of the molecule. One of the coordinated THF molecules could be removed by trituration with toluene and recrystallization of 1 from toluene to give [Sc(CH2Ph)3(THF)2] (2). A significantly different compound is obtained by starting the transmetalation reaction at −196 °C. Under these conditions the reaction of ScCl3 with KCH2Ph led to a two-dimensional coordination polymer of composition [Sc(CH2Ph)5K2(THF)3]n (3), in which the scandium atom is surrounded by five benzyl groups in a trigonal bipyramidal fashion. Under the same reaction conditions, but using LuCl3 as the starting material, the analogue of 1, [Lu(CH2Ph)3(THF)3] (4), is obtained, which can also be induced to lose a coordinated THF ligand to give [Lu(CH2Ph)3(THF)2] (5).