Formation and stabilities of cobalt dioxygen complexes in aqueous solution

Reversible Oxygenation of 2,4-Diaminobutanoic Acid-Co(II) Complexes

“…The volumetry results presented in Figure 6 show that 0.5 mmol of Co(DABA) 2 in aqueous solution can absorb approximately 5.6 mL of oxygen within 5 h. These results reveal that 1 mol of Co(DABA) 2 can take up 0.5 mol of oxygen and that the composition of the oxygenated complex is (CoL 2 ) 2 O 2 . This finding is consistent with the Co/O 2 ratio in His-Co(II) oxygen complexes [ 24 , 25 ].…”

A Structurally Characterised Pair of Dicobalt(III) Peroxo/Superoxo Complexes withC2-Symmetrical Tetrapodal Pentadentate Amine Ligands, and Some Reactivity en route

“…[6] This contrasts with a marked trans influence of the peroxo ligand (4) found in the structures of other CoN 5 complexes, where the CoϪN(trans) bond can be up to 3% longer than the other CoϪN bonds. [37,61] In the solid state, the central CoϪOϪOϪCo moiety of 5 is locked in a transoid conformation by four intramolecular hydrogen bonds indicated as dashed lines in Figure 1, defining the ''triangular'' arrangement N12ϪH12B⋅⋅⋅O1A⋅⋅⋅ H13AϪN13 and its symmetry-related counterpart [averaged distances and angles: d(N⋅⋅⋅O) ϭ 2.76 Å ; (NϪH⋅⋅⋅O) ϭ 126°]. Similar triangular intramolecular hydrogen bonding with planar CoϪOϪOϪCo units has been found in the complexes [(en)(dien)CoϪOϪOϪCo(dien)(en)](ClO 4 ) 4 , [62] [(tren)(NH 3 )CoϪOϪOϪCo(NH 3 )(tren)](SCN) 4 ⋅2H 2 O [63] and [(papd)CoϪOϪOϪCo(papd)](S 2 O 6 )(NO 3 ) 2 ⋅4H 2 O [34] (papd ϭ 1, 5,8,11,15-pentazapentadecane), and the adopted solid state conformations of bis[pentaaminecobalt(III)] peroxo cations have been discussed in terms of the balance of such intramolecular hydrogen-bonding interactions and lattice energy effects.…”

Separation of Oxygen from Air Using Coordination Complexes: A Review

“…The binding of dioxygen to cobalt(II) chelate complexes of Schiff base and cyclidene lacunar has been studied extensively. A number of papers, reviews, and books have in detail described the chemistry of cobalt dioxygen carriers (Norman et al, 1988a,b;Stephenson et al, 1991;Lin et al, 1991;Dzugan and Busch, 1990; Niederhoffer et al, 1984; Henrici-Olive and Olive, 1974; Fallab, 1967;Jones et al, 1979; Gubelmann and Williams, 1983;Basolo, 1974;Martell, 1982Martell, , 1988; Vatentine, 1973 Basolo et al, 1975;Vogt, 1963;Martel and Sawyer, 1988;Wilkins, 1971; Werner, 1910; Pauling and Coryell, 1936;Calvin and Martell, 1952).…”

“…Naturally, the details of dioxygen binding and transport in these proteins are of great interest to biochemists and numerous reviews of these and related subjects are available (Senozan, 1974(Senozan, , 1976; Weissbluth, 1974;Wang et al, 1979;Hayaishi, 1962;Bannister, 1977;Eichhorn, 1973;Sigel, 1978; Antonini and Brunori, 1971; Freedman et al, 1976;Kuntzetal., 1977). The structures and properties of these proteins, which are also of interest to chemists who design and study metal complexes as models for dioxygen transport proteins, have been reported in detail (Collman, 1977; Chang and Traylor, 1973b; Collman and Suslick, 1978;Bayer and Holzbach, 1977;Wang, 1970;Niederhoffer et al, 1984;Henrici-Olive and Olive, 1974;Fallab, 1967;Jones et al, 1979;Gubelmann and Williams, 1983;Basolo, 1974; Martell, 1982Martell, , 1988; Vatentine, 1973; Choy and O'connor, 1972/73; Erskine and Field, 1976; McLendon and Martell, 1976; Basolo et al, 1975;Vogt, 1963; McAuliffe, 1988; Coleman and Taylor, 1980;Martell and Sawyer, 1988).…”