Kinetics of reactions of Schiff-base complexes of iron(II). Part 6. The preparation and kinetics of reactions of complexes of multidentate ligands

Abstract

Preparations of iron(II) complexes of bi-, tri-, quadri-, quinque-, and sexi-dentate Schiff bases are reported. The Schiff-base ligands are derived from pyridine-2-carbaldehyde, phenyl 2-pyridyl ketone, pyridine-2,6-dicarb-aldehyde. or 2,6-diacetylpyridine, and appropriate amines. All these complexes aquate in acid solution, and react with cyanide to give ternary iron(II)–cyanide–Schiff-base complexes. The kinetics of aquation of several of these Schiff-base complexes, and the kinetics of cyanide attack at all the complexes, are described, and reactivities are compared with those for analogous reactions of other iron(II) di-imine complexes. Solvent effects on the re-activity with cyanide of one of the complexes of the sexidentate Schiff bases in a range of binary aqueous mixtures are discussed.