Fluorinated tris(pyrazolyl)borates.: Syntheses and characterization of sodium and copper complexes of [HB(3-(CF3),5-(Ph)Pz)3]-

Sodium salt of the fluorinated tris(pyrazolyl)borate ligand [HB(3-(CF3),5-(Ph)PZ)(3)](-) has been synthesized from the corresponding pyrazole and NaBH4 in high yield. It forms stable adducts with oxygen-based donors like THF and water. [HB(3-(CF3),5(Ph)PZ)(3)]Na(THF) is monomeric in the solid state whereas {[HB(3-(CF3),5-(Ph)PZ)(3)]Na(H2O)}(n) forms a polymeric chain structure. These tris(pyrazolyl)borato sodium adducts show intra, and/or inter-molecular sodium-fluorine interactions. X-ray crystal structures of [HB(3,5-(CF3)(2)PZ)(3)]Na(OEt2) and {[HB(3-(CF3),5-(CH3)PZ)(3)]Na(H2O)}(2) also display similar CF...Na contacts. The copper carbon monoxide complex [HB(3-(CF3),5-(Ph)PZ)(3)]CuCO was prepared by treating [HB(3-(CF3),5-(Ph)PZ)(3)]Na(THF) with CuOTf in the presence of CO. The infra-red stretching frequency data show relatively high v(CO) value (2103 cm(-1)) indicating the presence of highly electrophilic copper site on [HB(3-(CF3),5-(Ph)PZ)(3)]CuCO. Crystal structure of 3-(CF3),5-(Ph)PzH is also reported. It forms "tub" shaped tetramers in the solid state. (C) 2003 Elsevier Ltd. All rights reserved.