Synthesis Characterization and Biological Screening of Tri-benzyl tin(IV) Complexes of Some Schiff Bases Wajid Rehman, a * Amin Badshah, b Musa Kaleem Baloch, a Saqib Ali, b Gulzar Hameed a and Khalid M. Khan c a Department of Chemistry, Gomal University, Dera Ismail Khan, Pakistan b Department of Chemistry, Quaid-e-Azam University, Islamabad, Pakistan c HEJ Research Institute, University of Karachi, Karachi, Pakistan Synthesis and characterization of some novel di and tri-benzyl tin(IV) complexes of some Schiff bases are reported. The 1 H-NMR, 13 C-NMR, 119 Sn-NMR, IR, Elemental Analysis and 119 Sn Mössauber studies are made for structural determination. Spectroscopic data reveals that the ligand molecule is bound to the tin atom through oxygen. On the basis of spectroscopic data tetrahedral geometry is proposed for the synthesized com- pounds. The synthesized compounds have been tested against various microorganisms. The results obtained show that the synthesized compounds have promising activity against all the tested micro-organisms. Keywords: Schiff base; Organotin(IV) complexes; Tri-benzyl tin; Activity; Spectra. INTRODUCTION Schiff bases play an important role as ligands due to their ease of preparation and reactivity in organometallic chemistry. 1 Schiff base complexes of organotin(IV) moieties have been widely investigated and show excellent activity as fungicides, bactericides, anti-inflammatories, and as PVC stabilizers. 2-4 The increase of the industrial, agriculture and biological applications of organotin(IV) compounds during the last few decades has led to their accumulation in the envi- ronment and finally in the biological systems. However, the high phytotoxicty of these compounds towards many plants has restricted their practical use. 5 The most recent develop- ment in the field of organotin(IV) chemistry is their use as anti-tumor agents. Many di and tri-organotin(IV) complexes exhibit maximum anti-tumor activity combined with low tox- icity. 6-10 The importance of organotin moieties has been fur- ther enhanced during the past few decades due to their com- plexes with biologically important compounds. 11-27 In a pre- vious paper we synthesized organotin(IV) complexes of Male-imido-Acetic acid. 28 As a continuation, we are report- ing synthesis, characterization and biological elucidation of tri-benzyl tin(IV) complexes of some reported Schiff bases. 29 EXPERIMENTAL All the reactions were carried out under anhydrous and oxygen free atmosphere. The solvents used were dried before use according to the literature method. 30 The Schiff base tri-benzyl and I tin(IV) chloride were prepared according to the methods provided in the literature. 29,31 Schiff base II (compound II) was prepared by refluxing salicyldehyde and ethylenediamine (2:1) in benzene for 3 hours; the water mole- cules formed during the reaction were removed aziotropi- cally using Dean’s stark apparatus. The solid mass formed was recrystalized from dry acetone. The melting points were measured on a Reichert ther- mometer of F. G. Bode Co., Austria. IR spectra were obtained in KBr using a Perkin Elmer FT IR-1605 Spectrophotometer. Elemental analyses were carried out on a Yanaco MT-3 high-speed CHN analyzer with antipyrene as a reference compound. The 1 H- 13 C- and 119 Sn NMR spectra were re- corded on a multinuclear FT NMR 200 MHz of JEOL using TMS as an internal standard. Some of the 13 C spectra were measured on a Bruker AM 270 instrument at 50 MHz with 13 C probe. The Mössbauer spectra were recorded at 80 K on a Cryophysics instrument equipped with a 15 mCi Ca 119 SnO 3 source. Synthesis of Tri-benzyl tin(IV) Complexes of Schiff Bases Tri-ethyl amine chloride (20 mM) was added to a solu- tion of ligand (10 mM) dissolved in chloroform and the re- sulting mixture was refluxed for 2-3 hours; to this mixture tri-benzyl tin chloride (20 mM) in chloroform (50 mL) was Journal of the Chinese Chemical Society, 2004, 51, 929-934 929