O2 AND CO BINDING BEHAVIOR OF DOUBLE-SIDED PORPHYRINATOIRON(II) COMPLEXES MODIFIED BY AMIDE RESIDUES

New double-sided porphyrinatoiron(II) complexes having a polar cavity which includes an amide moiety (3,3-dimethylbutyryloxy)phenyl]-porphin atoiron(II) (1b) and -(3,3-dimethylbutyryloxy)phenyl]porphinatoiron(II ) (2b)) were synthesized. H-1 NMR spectroscopy indicated that the amid e residues are located on the porphyrin ring plane. The 02 and CO bind ing affinities of 1b and 2b were higher than those of (3,3-dimethylbut yryloxy)phenyl]porphinatoiron-(II) (4b), in response to the local pola rity in the cavity. The polar amide residue resulted in a decreased O2 dissociation rate. Thermodynamic parameters for the gaseous ligand bi ndings to the 2b complex were also determined.