154790-27-9Relevant academic research and scientific papers
Preparation of a Cobalt Analogue of Verdoheme by Coupled Oxidation of Cobalt(II) Octaethylporphyrin
Balch, Alan L.,Mazzanti, Marinella,Olmstead, Marilyn M.
, p. 269 - 270 (1994)
Conditions are reported which allow octaethylporphyrin cobalt(II) to be oxygenated to form the verdoheme analogue, octaethyloxaporphyrincobalt(III) dichloride, which has been isolated and characterized by X-ray diffraction.
Production of oxaporphyrin and biliverdin derivatives by coupled oxidation of cobalt(II) octaethylporphyrin
Balch, Alan L.,Mazzanti, Marinella,St. Claire, Tamara N.,Olmstead, Marilyn M.
, p. 2194 - 2200 (2008/10/08)
The ability of cobalt, rather than iron, to participate in the oxidative cleavage of porphyrins, a reaction related to that of the enzyme heme oxygenase, has been explored. Treatment of (octaethylporphyrin)cobalt(II) with dioxygen in the presence of ascorbic acid, as a reducing agent, in dichloromethane/tetrahydrofuran produces a green solution that can yield the cobalt verdoheme analogs [(OEOP)CoII](PF6) and {(OEOP)CoIIICl2} (OEOP is the monoanion of octaethyloxaporphyrin), {(OEB)Co}, a complex of the open chain tetrapyrrole octaethylbihndione (H3OEB), or octaethylbilindione itself. These products have been isolated and characterized by uv/vis and 1H NMR spectroscopy. [(OEOP)CoII](PF6)·CH2Cl2 (C36H45Cl2CoF6N6N 4OP) crystallizes in the triclinic space group P1 with a = 11.077(2) A?, b = 14.033(2) A?, c = 14.099(3) A?, α = 104.56(2)°, β = 101.70(2)°, and γ = 110.70(1)° at 130 K with Z = 2. Refinement of 4171 reflections with F > 4.0σ(F) and 450 parameters yielded R = 0.066; Rw = 0.060. The structure of the complex cation consists of a flat macrocycle with planar, four-coordinate cobalt at the center. These cations associate in π-π fashion with a mean-plane separation of 3.261 A? and a short lateral displacement of 1.506 A?. {(OEOP)CoIIICl2}·2CH2Cl2 (C37H47Cl6CoN4O) crystallizes in the monoclinic space group P21/c, with a = 12.702(5) A?, b = 8.125(3) A?, c = 19.327(5) A?, and β = 101.23(2)° at 130 K with Z = 2. Refinement of 1803 reflections with F > 4.0σ(F) and 218 parameters yielded R = 0.057; Rw = 0.054. The structure of the centrosymmetric complex consists of a six-coordinate cobalt ion with two axial chloride ligands and a planar oxaporphyrin which is disordered with regard to the location of the peripheral oxygen atom.
