Stability Constant of Transition Metal Complexes Aryl Schiff Bases

Abstract

Proton ligand stability constants of p-bromo-OHA -N -( 4' -methyl-
phenyl) imine (R₁), 5-bromo-OHA-N-(5-nitrophenyl) imine (R₂)
and 5-bromo-OHA-N-(2-chloro-5-nitrophenyl) imine (R₃) and
metal-ligand stability constants of their complexes with transition
metals Cu(II), Ni(II), Co(ll), Mn(II) and Cd(II) have been determined
at 25°, 35° and 45°C (± 0.1 ^oC) and μ = 0.1 M (NaCIO₄) in
50 : 50 ethanol-water medium. The thermodynamic parameters for
the formation of 1 : 1 and 1 : 2 complexes have been calculated.
The effect of substituent and the dependence of stability constants
on the atomic size has been discussed.