Exploring the coordinative behaviour and molecular architecture of new PhHg(II)/Hg(II) dithiocarbamate complexes

• Article reports new phenyl-mercury(II) and mercury(II) dithiocarbamate complexes.
• Complex 1 is binuclear and 6 is a 2-D polymeric chain built on Hg–S contacts.
• They show varied coordination patterns and supramolecular framework.
• Characterised by various spectroscopy and single crystal X-ray diffraction studies.
• Their photoluminescence behaviour has been studied.

New dithiocarbamate (dtc) complexes of the form [(PhHg)2L] (L = bis(furfurylaminomethyl)benzene dtc L1 (1)), [PhHg(L)] (L = ethyl-1-piperazinecarboxylate dtc L2 (2), thiomorpholine dtc L3 (3), N-(N-methyl-2-pyrrole)-N-(methyl-3-pyridyl) dtc L4 (4), N-(N′-methyl-2-pyrrole)-N-(methyl-benzyl) dtc L5 (5)) and [Hg(L)2] (L = bis(N-methyl-3-pyridyl) dtc L6 (6), L4 (7), L5 (8)) have been synthesized and fully characterised; their structures revealed by X-ray crystallography. 1–5 show similar structures with the metal atoms forming two strong bonds, to carbon and one sulfur atom from the bidentate ligand in an approximate linear arrangement with an additional weak bond to the second sulfur atom. However the complexes show very different packing arrangements. 1 is a less common type of dinuclear organomercury complex containing two dithiocarbamate units linked by a 1,4-dibenzyl group. In 6, the metal lies at the centre of a distorted square plane coordinated by two L6 ligands, axially bonded by sulfur atoms on the adjacent molecules in a 2-D polymeric chain. In 7 and 8 the Hg atom is tetrahedrally coordinated to four sulfur atoms from two bidentate ligands. Complexes 2, 5, 7 and 8 show luminescence in solution.

New PhHg(II)/Hg(II) complexes have been synthesised and fully characterised. Their crystal structures reveal varied coordination environment (linear, distorted tetrahedral and pseudo-octahedral) about the metal centres. To the best of our knowledge 1 formed with bis(furfurylaminomethyl)benzene dithiocarbamate ligand is the first example of a binuclear phenylmercury complex and 6, with bis(N-methyl-3-pyridyl)dithiocarbamate ligand generated a 2-D polymeric chain motif.Figure optionsDownload as PowerPoint slide