SYNTHESIS AND CHARACTERIZATION OF COPPER(II), ZINC(II), AND POTASSIUMCOMPLEXES OF A HIGHLY FLUORINATED BIS(PYRAZOLYL)BORATE LIGAND

Highly fluorinated, ydridobis(3,5-bis(trifluoromethyl)pyrazolyl)borate ligand, [H2B(3,5-(CF3)(2)Pz)(2)](-) has been synthesized and characte rized as its potassium salt. The copper(II) and zinc(II) complexes, [H 2B(3,5-(CF3)(2)Pz)(2)]Cu-2 and [H2B(3,5-(CF3)(2)Pz)(2)]Zn-2, have been prepared by metathesis of [H2B(3,5-(CF3)(2)Pz)(2)]K with Cu(OTf)(2) a nd Zn(OTf)(2), respectively. Ail the new metal adducts have been chara cterized by X-ray diffraction. The potassium salt is polymeric and sho ws several K ... F interactions. The Cu center of [H2B(3,5-(CF3)(2)Pz) (2)]Cu-2 adopts a square planar geometry, whereas the Zn atom in [H2B( 3,5-(CF3)(2)Pz)(2)]Zn-2 displays a tetrahedral coordination. Bis(pyraz olyl)borate ligands in the Zn adduct show a significantly distorted bo at conformation. The nature and extent of this distortion is similar t o that observed for the methylated analog, [H2B(3,5-(CH3)(2)Pz)(2)]Zn- 2. This Ligand allows a comparison of electronic effects of bis(pyrazo lyl)borate ligands with similar steric properties. Crystallographic da ta for [H2B(3,5-(CF3)(2)Pz)(2)]K: triclinic, space group <P(1)over bar >, with a = 8.385(1) Angstrom, b = 10.097(2) Angstrom, c = 10.317(1) A ngstrom, alpha = 104.193(9)degrees, beta = 104.366(6)degrees, gamma = 91.733(9)degrees, V = 816.5(3) Angstrom(3), and Z = 2. [H2B(3,5-(CF3)( 2)Pz)(2)]Cu-2 is monoclinic, space group C2/c with a = 25.632(3) Angst rom, b = 9.197(1) Angstrom, c = 17.342(2) Angstrom, beta = 129.292(5)d egrees, V = 3164.0(6) Angstrom 3, and Z = 4. [H2B(3,5-(CF3)(2)Pz)(2)]Z n-2 is triclinic, space group <P(1)over bar>, with a = 9.104(1) Angstr om, b = 9.278(1) Angstrom, c = 18.700(2) Angstrom, alpha = 83.560(6)de grees, beta = 88.200(10)degrees, gamma = 78.637(9)degrees, V = 1538.8( 3) Angstrom(3), and Z = 2. [H2B(3,5-(CH3)(2)Pz)(2)]Zn-2 is monoclinic, space group C2/c with a = 8.445(1) Angstrom, b = 14.514(2) Angstrom, c = 19.983(3) Angstrom, beta = 90.831(8)degrees, V = 2449.1(6) Angstro m 3, and Z = 4.