(π)C-H⋯S, (allyl)C-H⋯C(π) and π⋯π intermolecular interactions: Synthesis, characterization, and crystal structure of 2,2′-bipyridine bis(diallyldithiocarbamato)zinc(II)

A mixed-ligand Zn(II) complex formulated as [Zn(aldtc)₂(bipy)] (aldtc=diallyldithiocarbamate; bipy=2,2′-bipyridine) was synthesized and characterized by IR, ¹H and ¹³C NMR spectral measurements and X-ray crystallography. The crystal structure of this complex indicates that Zn has a distorted octahedral geometry. The Zn-N distances are invariant (2.168(2) Å), while those of the Zn-S are slightly different (2.5408(9) and 2.5440(9) Å). The N-Zn-N, S-Zn-S and N-Zn-S bond angles are in the range 75.35(13)-99.75(7)°, 70.48(3)-161.02(5)° and 95.26(7)-160.32(7) °, respectively. The crystal packing of the complex shows different motifs of supramolecularity resulting from both hydrophilic ((π)C-H⋯S) and hydrophobic ((allyl)C-H⋯C(π)) intermolecular interactions. These interactions result in a chain arrangement of molecules along crystallographic c axis and the chains are further connected via π⋯π stacking along with ((π)C-H⋯S along b axis leading to an overall crystal packing that can be regarded as layers of complexes along bc plane, which are held together through nonconventional hydrogen bonding and π⋯π stacking.