Thermodynamic Studies of the Interaction of Nickel(II) Schiff Base Complexes with Diorganotin (IV) Dichlorides in Non‐Aqueous Solvents

Abstract

A UV‐Vis spectrophotometric study of the adduct formation of the nickel(II) Schiff base complexes, ([NiL]) where L= [Salen, N,N′‐bis(salicylaldehydo)ethylenediimine], [Salpn, N,N′‐bis(salicylaldehydo)‐1,3‐propanediimine] and [Salophen, N,N′‐bis(salicylaldehydo)‐1,2‐phenylenediimine] as donors with R2SnCl2 (R=methyl and n‐butyl) as acceptors have been investigated in anisole, chloroform, N,N‐dimethylformamide (DMF) and methanol, as solvents. Adducts have been characterized by 1H NMR, IR and electronic spectroscopy. The formation constants and the thermodynamic free energies were measured using UV‐Vis spectrophotometry titration for 1∶1 adduct formation at 25°C. The trend of the adduct formation of a given nickel Schiff base complex with a given tin acceptor in the solvents used decreases as follows: Methanol>DMF>Anisole>Chloroform. The formation constants of the nickel Schiff base complexes with a given tin acceptor in a given solvent decreases according to the following trend: Ni(Salpn)>Ni(Salen)> Ni(Salophen). The sequence of the reaction of R2SnCl2 acceptors toward a given nickel Schiff base complex in a given solvent is as follow: Me>n‐Bu.