Crystal structure of bis[N-(2-hydroxyethyl)-N-methyldithiocarbamato-κ2 S,S′](pyridine)zinc(II) pyridine monosolvate and its N-ethyl analogue

Abstract

The common structural feature of the title compounds, [Zn(C4H8NOS2)2(C5H5N)]·C5H5N (I) and [Zn(C5H10NOS2)2(C5H5N)]·C5H5N (II), which differ by having dithiocarbamate N-bound methyl (I) and ethyl (II) groups, is the coordination of each ZnII atom by two non-symmetrically chelating dithiocarbamate ligands and by a pyridine ligand; in each case, the non-coordinating pyridine molecule is connected to the Zn-containing molecule via a (hydroxy)O—H...N(pyridine) hydrogen bond. The resulting NS4 coordination geometry is closer to a square-pyramid than a trigonal bipyramid in the case of (I), but almost intermediate between the two extremes in (II). The molecular packing features (hydroxy)O—H...O(hydroxy) hydrogen bonds, leading to supramolecular chains with a zigzag arrangement along [10-1] (I) or a helical arrangement along [010] (II). In (I), π–π [inter-centroid distances = 3.4738 (10) and 3.4848 (10) Å] between coordinating and non-coordinating pyridine molecules lead to stacks comprising alternating rings along the a axis. In (II), weaker π–π contacts occur between centrosymmetrically related pairs of coordinating pyridine molecules [inter-centroid separation = 3.9815 (14) Å]. Further interactions, including C—H...π(chelate) interactions in (I), lead to a three-dimensional architecture in each case.