Synthesis of [(C5H5Y (η2-PzMe2)(η-PzMe2)]2 and [Y(η2-PzMe2)2(η-PzMe2)(η-THF)]2 and the insertion of Me2SiO into the Y-N bond

Abstract

3,5-Dimethylpyrazole (HPzMe2) reacted with (C5H5)3Y in THF to yield dinuclear complexes [(C5H5)Y-(η2-PzMe2)(η-PzMe2)]2 (I) and [Y(η2-PzMe2)2(η-PzMe2)-(η-THF)]2 (II), revealing a new method for synthesizing tris(pyrazolate) complexes of lanthanide metals. The X-ray crystallographic analysis showed that complex II crystallizes in space groupP ·· − , with unit cell dimensionsa = 1.0798(1),b = 1.0818(1),c = 1.1313(1) nm, α = 76.914(2)°, β = 68.940(2)°, γ= 60.510(2)°,V= 1.0715(2) nm3, Z= 1. The finalR factor is 0.0445. The investigation results showed that Me2SiO can only be inserted into the Y-N (bridging) bond of complex I to form [(C5H5)Y(η2-PzMe2)(η-OSiMe2 PzMe2)]2 (III), but cannot be inserted into the Y-N (bridging) bond of complex II due to the bulky crowding of the tetraple bridge structure.