Synthesis and structural characterization of a disulphide-bridged tetranuclear palladium(II) complex derived from 3,5-diacetyl 1,2,4-triazole bis(4-ethylthiosemicarbazone)

A novel tetranuclear [Pd4(μ2-η2-S2)(H2L1)2] complex, where H2L1 is the anion of 3,5-diacetyl-1,2,4-triazole bis(4-ethylthiosemicarbazone), was synthesized and structurally characterized by single crystal X-ray diffraction. The molecular structure shows an unexpected μ2-η2-S2 bridge, which is shared by all the four palladium atoms. Each trideprotonate 3,5-diacetyl-1,2,4-triazole bis(4-ethylthiosemicarbazone) ligand acts as a hexadentate in a symmetrical manner bridging two metal ions through the two adjacent nitrogen atoms of the central triazole ring. The molecular packing is characterized by hydrogen bond interactions to form a 3D supramolecular architecture with channels running down the c∗ axis in which the lattice water molecules are encapsulated.