Crystal structure of bis-[ N-(2-hy-droxy-eth-yl)- N-methyl-dithio-carbamato-κ2S, 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 di-thio-carbamate N-bound methyl (I) and ethyl (II) groups, is the coordination of each Zn^II atom by two non-symmetrically chelating di-thio-carbamate ligands and by a pyridine ligand; in each case, the non-coordinating pyridine mol-ecule is connected to the Zn-containing mol-ecule via a (hy-droxy)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 inter-mediate between the two extremes in (II). The mol-ecular packing features (hy-droxy)O-H⋯O(hy-droxy) hydrogen bonds, leading to supra-molecular 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 mol-ecules lead to stacks comprising alternating rings along the a axis. In (II), weaker π-π contacts occur between centrosymmetrically related pairs of coordinating pyridine mol-ecules [inter-centroid separation = 3.9815 (14) Å]. Further inter-actions, including C-H⋯π(chelate) inter-actions in (I), lead to a three-dimensional architecture in each case.

Keywords: crystal structure; di­thio­carbamate; hydrogen bonding; pyridine adduct; zinc.

Figure 1

The mol­ecular structures of (a) (I) and (b) (II), showing the atom-labelling scheme and displacement ellipsoids at the 70% probability level.

Figure 2

Overlay diagram of the asymmetric units of (I), red image, and (II). The mol­ecules have been overlapped so the more symmetrically coordinating di­thio­carbamate ligands are coincident.

Figure 3

Mol­ecular packing in (I): (a) supra­molecular zigzag chain aligned along [10] and sustained by O—H⋯O hydrogen bonding, with the solvent pyridine mol­ecules attached via O—H⋯N hydrogen bonding, (b) a view of the unit-cell contents in projection down the a axis and (c) supra­molecular chain along the b axis sustained by (pyridine)C—H⋯π(chelate ring) inter­actions. The O—H⋯O, O—H⋯N, C—H⋯O, π–π and C—H⋯π(chelate ring) inter­actions are shown as orange, blue, brown, purple and pink dashed lines, respectively.

Figure 4

Mol­ecular packing in (II): (a) supra­molecular helical chain aligned along [010] and sustained by O—H⋯O hydrogen bonding, with the solvent pyridine mol­ecules attached via O—H⋯N hydrogen bonding, and (b) a view of the unit-cell contents in projection down the a axis. The O—H⋯S, O—H⋯N, C—H⋯S and π–π inter­actions are shown as orange, blue, pink and purple dashed lines, respectively.