99783-15-0Relevant academic research and scientific papers
CROWN THIOETHER CHEMISTRY. SYNTHETIC, STRUCTURAL, AND PHYSICAL STUDIES OF THE Cu(II) AND Cu(I) COMPLEXES OF HEXATHIA-18-CROWN-6
Hartmann, JudithAnn R.,Cooper, Stephen R.
, p. 1202 - 1208 (1986)
The copper(II) and copper(I) complexes of hexathia-18-crown-6 have been synthesized and characterized by electron paramagnetic resonance, electrochemical, and X-ray diffraction methods.The copper(II) complex, (picrate)2, crystallizes in the triclinic system, space group P1/, with a = 6.661(1) Angstroem, b = 9.669(2) Angstroem, and c = 13.594(3) Angstroem, α = 84.84(2)deg, β = 75.52(2)deg, and γ = 76.80(2)deg, and Z = 1.The copper(i) complex, (BF4), crystallizes in the orthorhombic system, space group Pna21, with a = 10.855(4) Angstroem, b = 18.592(7) Angstroem, c = 10.137(4) Angstroem, and Z = 4.The centrosymmetric copper(II) complex adopts an axially elongated octahedral geometry, with Cu-S(eq) distances of 2.323(1) and 2.402(1) Angstroem and a Cu-S(ax) distance of 2.635(1) Angstroem.Glasses at 77 K of (picrate)2 in 1:1 nitromethane-toluene yield an EPR spectrum with gx = 2.028, gy = 2.035, and gz = 2.119, Α = 0.0153 cm-1, and Α ca. o.0019 cm-1.The copper(I) complex assumes a distorted four-coordinate geometry that can be considered as derived from a linear two-coordinate complex by addition of two thioether groups; Cu-S distances are 2.253(2) and 2.245(2) and 2.358(2) and 2.360(2) Angstroem, repectively, for these two types of ligands.Cyclic voltammetry shows that the Cu(II) and Cu(I) complexes are connected by an essentially reversible one-electron redox process at very high potential: +0.96 V vs.NHE.
