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 I from toluene to give [Sc(CH2Ph)(3)(THF)(2)] (2). A significantly different compound is obtained by starting the transmetalation reaction at -196 degrees C. Under these conditions the reaction of ScCl3 with KCH2Ph led to a two-dimensional coordination polymer of composition [Sc(CH2Ph)(5)K-2(THF)(3)]. (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).