NEW STABLE GALLIUM(III) AND INDIUM(III) COMPLEXES WITH THIOSEMICARBAZONIC LIGANDS

The aim of this work is exploring a new library of coordination compounds for medicinal ap-plications. Gallium is known for several uses in this field [1-7], and the mechanisms behind these applications are different and require opposite chemical characteristics [7-8]. Indium is not that important in medicine in present time [9] but share a lot of chemical traits with its above-mentioned lighter companion and is applied in radioimaging as well [10-12]. Those metals were combined with thiosemicarbazones, which are ligating compounds increasingly known for their biological and pharmaceutical applications [13-20]. In particular, the few ligands [17] which were chosen to interact with these hard metal ions share the ideal affinity for high charge density. Therefore, with this work we describe how we synthesized and characterized the resulting coordination compounds. The yields of the reactions vary from a minimum of 21% to a maximum of 82%, using a fast and easy procedure. NMR and IR spectroscopy, mass spectrometry, elemental analysis and XRD (of only one complex, see in Figure 1) inform about the formation of stable compounds in every case, and about a ligand-to-metal 2:1 stoichiometry with both cations. In addition, we investigated deeper their chemical and biological characteristics, via UV-visible titrations, stability tests, and cytotoxicity and antibiotic assays. The results seem to address for a strong stability in each explored condition, which can be interesting for a radio-imaging application rather than an antitumoral or antimicrobic one.