Metal-templated condensation of cyclohexanedione dioxime and phenylboronic acid in the presence of Fe(II)sulfate heptahydrate proceeds cleanly in methanol to furnish the Fe(II) clathrochelate. An organic/inorganic hybrid membranescomposed of Fe(II) clathrochelate and polyethersulfone was prepared by using phase inversion method. For membranepreparation, the Fe(II) clathrochelate was highly soluble (3∼5 g/L) in DMF, NMP, and DMAc, which meets the requirementsfor the solubility of metal complexes in polar aprotic solvent used in membrane preparation. It was stable evenin the presence of strong acids, such as trifluorosactic acid (pKa = 0.3). It was characterized by UV-vis spectroscopy, andtheir stability in solution phase studied in the presence of (i) strong acids or (ii) competing chelates. Organic/inorganic hybridmembranes were prepared with polyethersulfone, polyvinylpyrrolidone, p-toluenesulfonic acid, Fe(II) clathrochelate andDMF by using nonsolvent induced phase inversion method. The addition of Fe(II) clathrochelate leads increase of surfacepore density, mean pore size and flux. We can obtain highly asymmetric membranes by addition of Fe(II) clathrochelate.