Synthesis, characterization, and biological evaluation of seven organotin (IV) complexes with a 5-thio-tetrazole carboxylate ligand derived from the Bargellini reaction

The organometallic tin(IV) carboxylates are, in general, well known; however, the corresponding organotin(IV) tetrazole-carboxylates are not known, despite their interest in function of the presence, in these bifunctional ligands, of a rigid tetrazole ring and a flexible carboxylate anion with the possibility of a wide structural diversity and relevant biological activity. In consequence, we report here the synthesis and full characterization of seven new organotin(IV) complexes with a 5-thio-tetrazole carboxylate ligand, the anion of the 2-methyl-2-[(1-phenyl-1H-tetrazol-5-yl)sulfanyl)]-propanoic acid obtained from the Bargellini reaction. The reaction of Bargellini is a source of economical synthesis of compounds in a multi-component reaction with an increase in complexity and functionality; however, its use in the synthesis of ligands for the obtention of new metal complexes is very limited. Therefore, another reason for this study lies in the convenience of broadly showing the usefulness of this reaction in the synthesis of ligands suitable for coordination chemistry. The new complexes were characterized by common spectroscopic techniques, and elemental analysis, and four of the complexes by single-crystal X-ray diffraction, whose structures are discussed, and the complexes were tested for their antibacterial capacities.

Automated summary

Organometallic tin(IV) carboxylates are well known, but the corresponding organotin(IV) tetrazole-carboxylates have not been discovered yet. This study reports the synthesis and characterization of seven new organotin(IV) complexes with a 5-thio-tetrazole carboxylate ligand, which possess a rigid tetrazole ring and a flexible carboxylate anion, allowing for a wide range of structural diversity and potential biological activity. The complexes were tested for their antibacterial capacities.