Intraction of Diorganotin (IV) with Copper Schiff base complexes: Synthesis, Characterization and Adduct Formation Studies

The equilibrium constant and the thermodynamic parameters were spectrophotometrically measured for the 1:1 adduct formation of the copper (II) Schiff base complexes [CuL] where L= Methyl-2-{N-[2-(2-hydroxy-5-methoxyphenyl)methylidynenitrilo]-ethyl}amino -1-cyclopentenedithiocarboxylate, (H2cd5OMesalen); Methyl-2-{N-[2-(2-hydroxy-5-bromo-phenyl)methylidynenitrilo]ethyl}amino-1-cyclopentenedithiocarb-oxylate, (H2cd5Brsalen); Methyl-2-{N-[2-(2-hydroxy-5-nitrophenyl)methylidyn-enitrilo]ethyl} amino-1-cyclopentenedithiocarboxylate, (H2cd5NO2salen) [1,2] as donors with R2SnCl2 (R= Me, n-Bu) as acceptors in dimethylformamide (DMF) and methanol (MeOH) as solvents at 25°C. Adducts have been characterized by 1H, 119Sn NMR, IR and UV-Vis spectroscopy. Our results revealed the trend of adduct formation constants between Schiff base complexes as donors and tin(IV) as acceptor decreases as follow: [Cu(cd5OMesalen)] > [Cu(cd5Brsalen)] > [Cu(cd5NO2salen)]; Me2SnCl2> n-Bu2SnCl2 and DMF > MeOH.