Design, synthesis and structural characterization of a novel asymmetric hydrazone-thiosemicarbazone ligand with the aim of obtaining interesting metallosupramolecular architectures

The asymmetric hydrazone-thiosemicarbazone ligand H₂L was synthesized in two stages by means of a double condensation reaction. Firstly, one equivalent of phenyl-semicarbazide reacted with one equivalent of the dialdehyde 2,6-diformylpyridine. Afterwards, the product formed was condensed with one equivalent of phenyl-thiosemicarbazide. The potentially dianionic and pentadentate [N₃SO] organic ligand H₂L possesses two flexibles bidentate [NS/NO] domains separated by a pyridine spacer which could stabilize a wide variety of metal ions, giving rise to different metallosupramolecular architectures. This ligand was fully characterized by different techniques such as elemental analysis, infrared spectroscopy, mass spectrometry and ¹H/¹³C NMR confirming that it was obtained with high purity.