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

The common structural feature of the title compounds, [Zn(C(4)H(8)NOS(2))(2)(C(5)H(5)N)]·C(5)H(5)N (I) and [Zn(C(5)H(10)NOS(2))(2)(C(5)H(5)N)]·C(5)H(5)N (II), which differ by having di­thio­carbamate N-bound methyl (I) and ethyl (II) groups, is the coordination of each Zn(II) 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 NS(4) 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.