title: Synthesis and Characterization of Copper(II), Zinc(II), and Potassium Complexes of a Highly Fluorinated Bis(pyrazolyl)borate Ligand.
abstract: Highly fluorinated, dihydridobis(3,5-bis(trifluoromethyl)pyrazolyl)borate ligand, [H(2)B(3,5-(CF(3))(2)Pz)(2)](-) has been synthesized and characterized as its potassium salt. The copper(II) and zinc(II) complexes, [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu and [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn, have been prepared by metathesis of [H(2)B(3,5-(CF(3))(2)Pz)(2)]K with Cu(OTf)(2) and Zn(OTf)(2), respectively. All the new metal adducts have been characterized by X-ray diffraction. The potassium salt is polymeric and shows several K.F interactions. The Cu center of [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu adopts a square planar geometry, whereas the Zn atom in [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn displays a tetrahedral coordination. Bis(pyrazolyl)borate ligands in the Zn adduct show a significantly distorted boat conformation. The nature and extent of this distortion is similar to that observed for the methylated analog, [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn. This ligand allows a comparison of electronic effects of bis(pyrazolyl)borate ligands with similar steric properties. Crystallographic data for [H(2)B(3,5-(CF(3))(2)Pz)(2)]K: triclinic, space group P&onemacr;, with a = 8.385(1) Å, b = 10.097(2) Å, c = 10.317(1) Å, alpha = 104.193(9) degrees, beta = 104.366(6) degrees, gamma = 91.733(9) degrees, V = 816.5(3) Å(3), and Z = 2. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu is monoclinic, space group C2/c with a = 25.632(3) Å, b = 9.197(1) Å, c = 17.342(2) Å, beta = 129.292(5) degrees, V = 3164.0(6) Å(3), and Z = 4. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn is triclinic, space group P&onemacr;, with a = 9.104(1) Å, b = 9.278(1) Å, c = 18.700(2) Å, alpha = 83.560(6) degrees, beta = 88.200(10) degrees, gamma = 78.637(9) degrees, V = 1538.8(3) Å(3), and Z = 2. [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn is monoclinic, space group C2/c with a = 8.445(1) Å, b = 14.514(2) Å, c = 19.983(3) Å, beta = 90.831(8) degrees, V = 2449.1(6) Å(3), and Z = 4.
authors.affiliation: Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019.
authors.forename: H. V. Rasika
authors.initials: HV
authors.lastname: Dias
authors.forename: John D.
authors.initials: JD
authors.lastname: Gorden