New Bis-Diphenyltin(IV) Complexes With Oxalyldihydrazone Derivatives: Synthesis, Characterization And Antibacterial Activity

The new binuclear organotin(IV) complexes, (Ph2Sn)(2)L-a (1), (Ph2Sn)(2)L-b (2) and (Ph2Sn)(2)L-c (3), have been synthesized from reaction of Ph2SnCl2 with oxalyl dihydrazone derivatives, bis(2-hydroxy-1-naphthaldehyde)oxalyldihydrazone (H4La), bis(5-bromo-2-hydroxybenzaldehyde) oxalyldihydrazone (H4Lb), and bis(2-hydroxy-3-methoxybenzaldehyde)oxalyldihydrazone (H4Lc). The synthesized compounds have been investigated by elemental analysis and IR, H-1 NMR, and Sn-119 NMR spectroscopy. On the basis of these data, acyldihydrazone supplies two tridentate dianionic ONO domains and is coordinated to two diphenyltin(IV) moiety through the imine nitrogen and phenolic and enolic oxygen atoms. All complexes are binuclear and the coordination number of each tin is five. The in vitro antibacterial activity of ligands and complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria and compared with standard drugs. All complexes exhibit more inhibitory effects than the parent ligands and have a potential to be used as drugs.