Novel bifunctional zinc and magnesium Schiff-base complexes containing quaternary ammonium halide side-arms were developed. Zinc complex 1Et-I (0.02 mol%) having an iodide anion has shown the highest TOF for the propylene oxide/CO₂ coupling reaction of up to 459 h⁻¹. This TOF value was maintained even when the catalyst loading was reduced to 0.005 mol%.