REACTIONS OF OXYGENATED COBALT(II) COMPLEXES .10. 1,4,7,10-TETRAAZADECANECOBALT(II) AND 4,7-DIMETHYL-1,4,7,10-TETRAAZADECANECOBALT(II) AS DIOXYGEN CARRIERS

Reactions of oxygenated cobalt (II) complexes. X. 1,4,7,10‐tetraazadecanecobalt (II) and 4,7‐dimethyl‐1,4,7,10‐tetraazadecanecobalt (II) as dioxygen carriers Oxygenation of cobalt (II) chelates with fourdentate amines such as 1,4,7,10‐tetraazadecane (= tad) in aqueous solution yields μ‐peroxo‐μ‐hydroxo‐dicobalt (III) complexes. Due to facultative ligand disposition of the amine, 8 different diastereoisomers are possible. Introducing methyl groups in positions 4 and 7 of tad destabilizes the isomers with β‐configuration. A crystallized perchlorate, obtained by oxygenation of 4, 7‐dimethyl‐1,4,7,10‐tetraazadecanecobalt (II) (= dmtad) in alcaline solution, proved to be of the expected μ‐peroxo‐μ‐hydroxo type. The ligand configuration is and lattice constants a (ΔΔ/ΛΛ). The X‐ray structure was solved by Patterson's method and refined to R = 0.093. The crystals are orthorhombic with space group Pna21 and lattice constants a = 14.632 (4), b = 17.525 (5), c = 12.888 (5) Å. In its UV./VIS. absorption spectrum and its solution reactivity the binuclear cation is closely related to oxygenation products obtained with the chelate of unsubstituted tad. The kinetic parameters of the decomposition reaction of the μ‐peroxo complexes in acidic solution are compared. The binuclear cations with 4, 7‐dimethyl‐1,4,7,10‐tetraazadecane as ligand are generally more reactive. In slightly alcaline solution isomerization of the μ‐peroxo‐μ‐hydroxo complexes has been observed. Copyright © 1979 Verlag GmbH & Co. KGaA, Weinheim