Kinetic study of ligand release promoted by ammonium ion on bis(N-alkylsalicylaldiminato)zinc(II) complexes in aprotic solvent

Abstract The reaction between ammonium ion and bis( N -alkylsalicylaldiminato)zinc(II) complexes [Zn(R-sal) 2 ] (R-sal=anion of N -alkylsalicylaldimine; R=H, n-Bu=n-butyl, t-Bu=tert-butyl, i-Pr=iso-propyl, Et=ethyl) in dry acetonitrile, leads to the release of the ligand. The reaction was studied kinetically at different temperatures and an analysis by mean of a multi-wavelength stopped-flow technique evidences a first-order kinetic as a general rule, and a two exponential profile for the t-butyl substituted complex for the release of one of the bidentate ligands of the Zn(II) complexes. Kinetic and 1 H NMR data indicate that the first step of the release reaction of the ligand is the OZn bond breaking.