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Adsorption of molecular oxygen by polymer covalently bonded co(II) porhyrin complex in toluene
Author(s) -
Hasegawa Etsuo,
Kanayama Tatsuya,
Tsuchida Eishun
Publication year - 1978
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1978.360170309
Subject(s) - chemistry , adduct , covalent bond , oxygen , porphyrin , monomer , photochemistry , polymer chemistry , polystyrene , ligand (biochemistry) , polymer , electron paramagnetic resonance , organic chemistry , nuclear magnetic resonance , biochemistry , physics , receptor
Reaction betwenn molecular oxygen and polystyrene covalently bonded Co(II) protoporphyrin IX complex, which was prepaired by the incorporation of a cobaltous ion into the metal‐free porphyrin polymer, was studied in the presence of N ‐ethylimidazole by measuring visible absorption and electron spin resonance spectra. It was found that the complex forms a monomeric oxygen adduct reversibly at low temperature dependent on oxygen pressure. In the presence of molecular oxygen, a new electron spin resonance signal due to the oxygen complex at g iso =2.02 shows no superhyperfine splitting structure in fluid toluene solution even at −80 °C, but it was observed in frozen toulene glass solution at −120°C, The oxygen adducts of the complexes between C0(II) protoporphyrin IX dimethyl ester and N ‐ethylimidazole and copoly(styrene‐ N ‐vinylimidazole) showed eight resolved superhyperfine splitting at −40 and −60°C, respectively. The polymer covalently bonded Co(II) complex with N ‐ethylimidazole was oxidized at room temperature under oxygen atmosphere. It was suggested that a Co(II) porphyrin–oxygen adduct with an axial ligand may be oxidised monomolecularly at high temperature.