Fluorinated tris(pyrazolyl)borate ligands without the problematic hydride moiety:: Isolation of copper(I) ethylene and copper(I)-tin(II) complexes using [MeB(3-(CF3)PZ)3]-

The thallium derivative of a fluorinated, B-methylated, tris(pyrazolyl)borate ligand, [MeB(3-(CF3)Pz)(3)](-), has been synthesized via a two-step process using the corresponding pyrazole, Li[MeBH3], and thallium(I) acetate. Reaction of [MeB(3-(CF3)PZ)(3)]TI with CuBr in the presence of ethylene leads to [MeB(3-(CF3)Pz)(3)]Cu(C2H4). It is a thermally stable solid. [MeB(3-(CF3)Pz)(3)]CU(C2H4) reacts with [(Bn)(2)ATI]SnCl to yield [MeB(3-(CF3)PZ)(3)]Cu-Sn(Cl)[(Bn)(2)ATI], featuring an unsupported Cu(I)-Sn(II) bond [2.4540(4) angstrom].