Sn(IV) Compounds Interaction with Metal-Schiff Base Complexes

The formation constants and Gibbs free energy for the interaction of RnSnClm (n = m = 2, R = Me, Ph, n-Bu or n = 4, m = 0, R = Ph) compounds as acceptors, with ML complexes (H2L = N,Nʹ-bis(salicylidene)-2-aminobenzylamine (salabza-H2) and its derivatives, M = Mn2+ or Zn2+), as donors in N,Nʹ-dimethylformamide (DMF) as solvent were studied. These parameters were measured by using UV-vis spectrophotomety titration for 1:1 adduct formation of the selected complexes at 25 (±0.1) °C in the 200-500 nm regions. The trend of adduct formation constants between metal Schiff base complexes as donors and tin(IV) as acceptor decreases as follow: Me2SnCl2 > Ph2SnCl2 > n-Bu2SnCl2 > Ph4Sn [M(5-OMe-salabza)] > [M(salabza)] > [M(5-Br-salabza)] > [M(5-NO2-salabza)] Zn > Mn