Synthesis, crystal structures and luminescent properties of phenylmercury(II) complexes with thiohydrazone ligands having weak Hg····π and Hg····Hg interactions

The Reaction of phenylmercury(II) acetate with salicylaldehyde morpholine N-thiohydrazone (H2smth) and 2-hydroxyacetophenone morpholine N-thiohydrazone (H2apmth) in dry ethanol under gentle refluxing condition form light yellow complexes [PhHg(Hsmth)] (1) and [PhHg(Hapmth)] (2) involving formation of Hg-S bond from the thiol form of the ligands after deprotonation of the SH proton. The structures of the complexes as determined by X-ray crystallography shows that the complex (1) has a distorted T-shaped geometry while the complex (2) adopts familiar linear coordination geometry. Complex (2) has two independent molecules comprising the asymmetric unit. Both the complexes form two-dimensional supramolecular assemblies due to a combination of weak intermolecular Hg····π and Hg····Hg interactions. The Hg····π and Hg····Hg distances are 3.937 and 4.0216(10) Å, respectively, possibly indicating weak mercuriophilic interactions. The luminescent properties of the complexes in solution and in the solid state at room temperature are also described.

Graphical abstractThe Reaction of phenylmercury(II) acetate with salicylaldehyde morpholine N-thiohydrazone (H2smth) and 2-hydroxyacetophenone morpholine N-thiohydrazone (H2apmth) in dry ethanol under gentle reflux form light yellow complexes [PhHg(Hsmth)] (1) and [PhHg(Hapmth)] (2) involving formation of Hg–S bond from the thiol form of the ligands after deprotonation. Both the complexes form two-dimensional supramolecular assembly by combination of weak intermolecular Hg–π, Hg–Hg and C–H–π interactions. All the complexes in this study were found to exhibit rich luminescence properties in both solution and solid state.Figure optionsDownload full-size imageDownload as PowerPoint slide