Facilitated transport of molecular oxygen in the membranes of polymer-coordinated cobalt Schiff base complexes

(N,N′-Disalicylideneethylenediamine)cobalt(II) (CoS) forms a five-coordinate complex with poly[(octyl methacrylate)-co-(4-vinylpyridine)] (POMPy) or poly[(octyl methacrylate)-co-(1-vinylimidazole)] (POMIm), which binds molecular oxygen rapidly and reversibly even in the solid state through the vacant sixth coordination site. In the membranes of these polymer-coordinated CoS complexes molecular oxygen transport is facilitated, because the CoS complex effectively acts as a fixed carrier for the oxygen transport in the membranes. Oxygen-binding parameters determined spectroscopically were adequate to analyze the dual-mode transport model, by which the oxygen permeation behaviors are quantitatively discussed. Effects of the oxygen-binding capability and of the concentration of the CoS fixed carrier on the facilitated oxygen transport are also discussed by using the model.