Synthesis and characterization of tribenzyltin(IV) and dibenzyltin(IV) complexes of 2-{[(2Z)-3-hydroxy-1-methyl- 2-butenylidene]amino}acetic acid: Crystal structure of tribenzyl{2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene] amino}acetato}tin(IV)

Reactions of equimolar quantities of potassium 2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene]amino}acetate, with R n SnX4−n (R: benzyl– and n=2 or 3) in methanol yielded products of compositions LHSn(PhCH2)3 and LSn(PhCH2)2, respectively. The complexes were characterized by microanalysis, IR, NMR (1H, 13C, 119Sn) and 119mSn Mossbauer spectroscopy. A full characterization of the structure of the complex, tribenzyl{2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene]amino}acetato}tin(IV), was carried out by single crystal X-ray crystallography. The compound exists as centrosymmetric dimers in which two ligand molecules bridge the two tin centres. Each of the tin atoms in the dimeric unit is five coordinate in an approximately trigonal bipyramidal configuration, with carbon atoms in the equatorial positions and oxygen atoms arranged axially.