Two-dimensional supramolecular assembly of phenylmercury(II) and cadmium(II) complexes with a tridentate thiohydrazone NNS donor ligand: Synthesis, coordination behavior and crystal structure

The reaction of phenylmercury(II) acetate and cadmium(II) acetate with a refluxed solution of diacetylmonoxime and morpholine N-thiohydrazide formed a novel phenylmercury(II) complex, [PhHg(Hdammthiol)] (1) and a cadmium(II) complex, [Cd(Hdammthiol)2] (2), respectively (where H2dammthiol is the thiol form of diacetylmonoximemorpholine N-thiohydrazone (Hdammth) formed by the condensation of diacetylmonoxime and morpholine N-thiohydrazide in the presence of phenylmercury(II) and cadmium(II) ions). The complexes were characterised by elemental analyses and spectral data (electronic, infrared and 1H NMR) and also by X-ray crystal structure analysis. The X-ray crystallography shows that the phenylmercury(II) complex attained a tricoordinated distorted T-shaped structure, while the cadmium(II) complex attained a trapezoidal bipyramidal geometry. The phenylmercury(II) complex forms a two-dimensional sheet via C–H⋯O and O–H⋯N hydrogen bonding and also forms a two-dimensional supramolecular dimer, having C–H⋯π synthons. Intermolecular C–H⋯O and O–H⋯O hydrogen bonding of the cadmium(II) complex forms a two-dimensional supramolecular sheet along the bc plane and posses an impressively short intermolecular C(sp3)⋯O(sp3) contact.