Synthesis, spectral, and thermal studies of organotin(IV) complexes with 4-bromo-2-{[(2-hydroxyphenyl)imino]methyl}phenol

The organotin(IV) chlorides R2SnCl2 (R = Ph and Me) react with a Schiff base (H2L), obtained from the condensation of 5-bromo-2-hydroxybenzaldehyde and ortho-aminophenol. Spectral properties of new complexes were investigated by infrared (IR), H-1 NMR, and Sn-119 NMR spectroscopy and show that in the two complexes H2L acts as a tridentate dianionic ligand and co-ordinates to the metal via two phenolic oxygens and one imine nitrogen. The Sn-119 NMR data are consistent with the presence of five-coordinate tin(IV) in solution. Thermal decomposition of the complexes has been studied by thermogravimetry and the activation energy has been determined by the Horowitz-Metzger method.