O₂/n₂‐separation by polymer‐bound cobalt complexes

Facilitated or complexation‐mediated transport of oxygen in the solid membrane containing a fixed carrier was described, by using the polymer‐bound cobalt Schiff's base chelate (CoS) and cobaltporphyrin (CoP). α³ β‐Substituted cobaltporphyrin derivatives were synthesized: The oxygen‐binding reaction to cobalt was affected by the cavity structure on porphyrin, i.e., unbulky amido‐substituted groups such as acetylamido‐ and acrylamido‐substituents enhanced oxygen‐binding and ‐dissociation rate constant or provided an oxygen‐binding pathway. Oxygen transport through the membranes of these polymer‐bound CoP derivatives was selectively augmented due to the rapid and reversible oxygen‐binding. Diffusion constants via the fixed CoPs correlated to the characteristics of oxygen‐binding reaction.