Crystal and Molecular Structure of Di-μ-chloro-bis[chloro(5,8-dithiadodecane)copper(II)], [Cu(BuSCH₂CH₂SBu)Cl₂]₂

The crystal and molecular structure of the title compound has been determined from single-crystal three-dimensional X-ray data collected by counter methods. The compound crystallizes as dark green needles in space group Pi: Z = 1; a = 9.646 (3), b = 11.823 (4), c = 7.934 (2) A; a = 109.61 (2), 0 = 79.23 (2), y = 113.55 (2)°; dcM = 1.451, dobsi = 1.45 (1) g/cm3. Least-squares refinement of 2460 reflections having I>2 <r(I) gave a conventional R factor of 0.063. The complex crystallizes as discrete centrosymmetric dichloro-bridged dimers with five-coordinate Cu(II) ions bound by a bidentate thioether ligand and three Cl~ ions. An ideal square-pyramidal model is marginally superior to the trigonal-bipyramidal alternative for describing the CuS2Cl3 coordination geometry. Cu-S bond lengths (2.308 (2), 2.369 (2) A) and Cu-Cl bond lengths (2.266 (2), 2.242 (2) A) within the puckered cw-CuS2Cl2 fragment are typical for equatorial bonding of these types. The copper atom is displaced 0.26 A from this S2C12 plane toward an apically bonded chloride ion (Cu-Cl = 2.825 (2) A). Structural parameters for the planar Cu2Cl2 bridging unit include Cu-Cl bond distances of 2.825 (2) and 2.266 (2) A, Cu-Cl-Cu' bond angles of 94.22 (5)°, and a Cu-Cu separation of 3.749 (2) A.