Reversible dioxygen binding

Figure 2.3 Structures of two globin compounds capable of reversible dioxygen binding. From Lippard and Berg, 1994. Reproduced by permission of University Science Books.

Figure 4.13 Co(acacen), an early model compound exhibiting reversible dioxygen binding at low temperatures.

Another gradient-corrected density functional study of reversible dioxygen binding and reversible 0-0 bond cleavage has been carried out for Cu2(p-T 2 r 2... 

FIGURE 4.9 Representative sterically constrained porphyrins designed for reversible dioxygen binding to their Fe(II) or Co(II) complexes.31... 

The differences in oxygen affinities are determined by the rates of O2 binding rather than O2 dissociation (Figure 4.11, Table 4.3). For a reversible dioxygen binding process depicted in Equation 4.5, the observed oxygenation rate constant depends linearly on the concentration of O2 ... 

The common thread that relates hemerythrin, MMO, and ribonucleotide reductase is the involvement of dioxygen with a diiron active site. For hemerythrin, reversible dioxygen binding is its function and much is known of this chemistry. For MMO and ribonucleotide reductase, the role of dioxygen and its mechanism of activation is just beginning to emerge. 

Figure 16. Proposed mechanism for reversible dioxygen binding in hemerythrin. Adapted from Ref. 2.

Insertion of iron into the Q-capped porphyrin, followed by reduction, gave a crystalline four-coordinate high spin iron(II) porphyrin 166 (Scheme 46). In solutions containing excess axial base the five-coordinate heme was formed which was capable of reversible dioxygen binding at 25 °C. The stability of the dioxygen adduct depended on... 

Sharma, A.C. Borovik, A.S. Design, s5nthesis, and characterization of templated metal sites in porous organic hosts application to reversible dioxygen binding. J. Am. Chem. Soc. 2000, 122, 8946-8955. 

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