Diorganotin(IV) Complexes with Monohydrate Disodium Salt of Iminodiacetic Acid: Synthesis, Characterization, Crystal Structure and Biological Activities

Diorganotin(IV) derivatives have been synthesized by the reaction of R2SnL2 (R = n-Bu 1, Ph 2) with monohydrate disodium salt of iminodiacetic acid (Na2L) in 1:1 M/L ratio under reflux conditions. The compounds have been characterized by FT-IR, NMR (H-1 and C-13) spectoscopy, electron ionization mass spectrometry (EIMS), thermogravimetric analyses (TGA) and single crystal XRD. FTIR data indicates a mono-dentate binding mode of the carboxylic acid group as well as participation of the amino nitrogen and aqua oxygen in coordination with organotin(IV) moieties. NMR data demonstrates a tetra-coordinated environment around tin(IV) in solution. Mass spectrometric and thermogravimetric analyses verify the close similarities between the molecular structures of both complexes. The thermal stability of diphenyltin(IV) derivative (2) was found slightly higher than that of the free ligand (Na2L). Single crystal X-ray analysis of the complex 1 have shown a hexa-coordinated geometry around Sn(IV) with trans configuration. There are evidences for the existence of intermolecular hydrogen bonding in the structure of the complexes. The products displayed significant antibacterial and antifungal activities in contrast to the biologically inactive ligand precursor. However, the hemolytic cytoxicity of the complexes was comparatively high than the free ligand.