COPPER COORDINATION-COMPOUNDS OF THE LIGAND 1,6-BIS(3,5-DIMETHYL-1-PYRAZOLYL)-2,5-DITHIAHEXANE (BDDH) - X-RAY STRUCTURES OF [CU(BDDH)]2(BF4)2, [CU(BDDH)CL]2CUCL4 AND [CU(BDDH)(3,5-DIMETHYL-PYRAZOLE)](BF4)2

The new ligand 1,6-bis(3,5-dimethyl-1-pyrazolyl)-2,5-dithiahexane (bddh) rendered the following coordination compounds with copper(I) and copper(II) salts: Cu(bddh)(NO3)2, [Cu(bddh)(H2O)](BF4)2, [Cu(bddh)Cl]2CuCl4, [Cu(bddh)(Hdmpz)](BF4)2 (Hdmpz = 3,5-dimethylpyrazole), [Cu(bddh)Cl]BF4, [Cu(bddh)]2(BF4)2, Cu(bddh)Cl and Cu(bddh)Br. The compound [Cu(bddh)Cl]2CuCl4 crystallizes from ethanol in the monoclinic space group Cc, with a = 19.018(4), b = 14.840(3), c = 14.963(3) angstrom, beta = 100.24(2), V = 4158 angstrom 3, Z = 4 and D(calc) = 1.63 g cm-3. The refinement using 5145 measured and 1826 observed (F > 2-sigma(F) reflections resulted in the R values 0.062 (R) and 0.068 (R(w)). The asymmetric unit consists of two [Cu(bddh)Cl]+ cations and a CuCl4(2-) anion. The copper(II) atom in [Cu(bddh)Cl]+ cation is coordinated by two pyrazole nitrogen atoms in trans position (1.991(9) and 1.98(1) angstrom), two thioether atoms in cis position (2.422(3) and 2.480(3) angstrom) and one chloride atom (2.249(4) angstrom) in a distorted trigonal bipyramid with the nitrogen donors on axial positions and the two sulfurs and chloride in the equatorial plane. The tetrahedral CuCl4(2-) anion lies in disorder. The compound [Cu(bddh)(Hdmpz)](BF4)2 crystallizes from ethanol in the monoclinic space group P2(1)/c, with a = 18.360(3), b = 9.419(3), c = 16.068(2) angstrom, beta = 100.29(1), V = 2734 angstrom 3, Z = 4 and D(calc) = 1.55 g cm-3. The refinement using 6883 measured and 2326 observed (F > 2-sigma(F)) reflections resulted in the R values 0.55 (R) and 0.061 (R(w)). The asymmetric unit consists of a [Cu(bddh)(Hdmpz)]2+ cation and two tetrafluoroborate anions. The copper(II) atom is coordinated by three pyrazole nitrogen atoms (1.987(6) and 1.962(6) angstrom; Hdmpz: 1.977(6) angstrom) and two sulfur atoms (2.478(2) and 2.404(3) angstrom) in a distorted trigonal bipyramid, with the ligand pyrazole groups on axial positions. The copper(I) compound [Cu(bddh)]2(BF4)2 crystallizes from ethanol in the monoclinic space group C2/c, with a = 22.679(2), b = 12.766(2), c = 14.213(2) angstrom, beta = 106.69(1), V = 3942 angstrom 3, Z = 8 and D(calc) = 1.55 g cm-3. The refinement using 1495 observed (F > 2.5-sigma(F)) reflections resulted in the R values 0.049 (R) and 0.082 (R(w)). The cationic part of the compound is dinuclear with C2 symmetry. The copper(I) ions are 4.603(3) angstrom apart. Each copper(I) ion is coordinated by a pyrazole nitrogen atom at 2.067(6) angstrom and two thioether atoms at 2.426(2) and 2.333(3) angstrom from one ligand and by a pyrazole nitrogen at 1.980(8) angstrom of another ligand in a strongly distorted tetrahedral fashion. Spectroscopic results strongly suggest that the compounds [Cu(bddh)(H2O)](BF4)2 and [Cu(bddh)Cl]BF4 contain the trigonal bipyramidal [Cu(bddh)A] unit (A = anion), as present in [Cu(bddh)Cl]2CuCl4 and [Cu(bddh)(Hdmpz)](BF4)2. The compounds Cu(bddh)Cl and Cu(bddh)Br are IR and X-ray isomorphous.