NOVEL TRIS(PYRAZOLYL)BORATES BEARING PERFLUOROALKYL PIGTAILS - SYNTHESES AND CHARACTERIZATION OF THE SODIUM AND COPPER(I) COMPLEXES OF [HB(3-(R)PZ)(3)](-) (R=C2F5, C3F7, PZ=PYRAZOLYL)

3-(Pentafluoroethyl)pyrazole and 3-(heptafluoropropyl)pyrazole were sy nthesized and fully characterized. These pyrazoles react with NaBH4 to yield sodium salts of [HB(3-(C2F5)-Pz)(3)](-) and [HB(3-(C3F7)Pz)(3)] (-). The X-ray crystal structure of [HB(3-(C2F5)Pz)(3)]Na(3-(C2F5)-PzH ) shows close contacts between the sodium atom and fluorine atoms of t he -C2F5 substituents. The copper-carbon monoxide adducts [HB(3-(C2F5) zP)(3)]CuCO and [HB(3-(C3F7)Pz)(3)]CuCO were prepared by the treatment of CuOTf with 1 equiv of the corresponding tris(pyrazolyl)boratosodiu m under CO. The copper and sodium complexes were characterized by H-1, C-13, and F-19 NMR and IR spectroscopies. IR spectroscopic data of [H B(3-(CF3)Pz)(3)]-CuCO, [HB(3-(C2F5)Pz)(3)]CuCO, and [HB(3-(C3F7)Pz)(3) ]CuCO did not exhibit a significant difference in the vco values, but they are notably lower than the corresponding v(CO) values of the 3,5- disubstituted analog [HB(3,5-(CF3)(2)Pz)(3)]CuCO.