Double-sided porphyrinatoiron(II) complexes bearing covalently bound axial imidazole, 5-[2-(5-imidazolylvaleryloxy)-6-(pivaloyloxy)phenyl]-10,15,20-tris[2,6- bis(pivaloyloxy)phenyl]porphyrinatoiron(II) and 5-[2-(3,3-dimethylbutyryloxy)-6-(5-imidazolylvaleryloxy)phenyl]-10,15,20-tris[2, 6-bis(3,3-dimethylbutyryloxy)phenyl]porphyrinatoiron(II), have been synthesized. On the basis of their absorption and 1H NMR spectra, the axial imidazole group is co-ordinated. The complexes reversibly form stable dioxygen adducts in toluene at 25 °C, and the kinetics of binding of O2 and CO has been investigated. When embedded in phospholipid unilamellar vesicles, the complexes possess the ability to transport dioxygen in an aqueous medium. The binding affinity of the pivaloyloxy derivative [P1/2(O2) = 27 Torr] is equal to that of a red blood cell suspension and the half-life of the dioxygen adduct formed was 1.5 d under physiological conditions (pH 7.4, 37 °C).
|Number of pages||5|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - 1993|
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