Monodentate and Bridging Bidentate Functions of 4,4′-Bipyridine in the Crystal Structures of [Zn(4,4′-Bipy){(n-C₃H₇)₂NCS₂}₂] and [Zn₂(4,4′-Bipy){(n-C₃H₇)₂NCS₂}₄]

Abstract

The structures of the mixed-ligand complexes Zn(4,4′-Bipy){(n-C₃H₇)₂NCS₂}₂ (I) and Zn₂(4,4′-Bipy){(n-C₃H₇)₂NCS₂}₄ (II) were determined by single crystal X-ray diffractometry (CAD-4 diffractometer, MoK_α radiation, 2479 and 1616 F_hkl, R = 0.0550 and 0.0523). The crystals are monoclinic with cell parameters a = 16.560(2), b = 11.423(1), c = 15.319(2) Å, β = 94.27(1)°, V = 2889.8(6) ų, Z = 4, space group P2₁/c (for I) and a = 8.515(1), b = 10.965(1), c = 27.816(3) Å, β = 95.860(1)°, V = 2583.5(5) ų, Z = 2, space group P2₁/n (for II). The structure of I is composed of discrete mononuclear molecules; the structure of II consists of discrete centrosymmetric binuclear molecules. The coordination polyhedra of the Zn atoms (c.n. 5) are formed by four S atoms of the two cyclic bidentate dithiocarbamate ligands and the N atom of the 4,4′-Bipy ligand, which is monodentate in I and bridging bidentate in II. Molecular packings and interactions in the structures are considered.