Salcomine crystallizes as a dimer. In this form, the cobalt centers achieve five-coordination via a bridging phenolate ligands.[5] A monomeric form crystallizes with chloroform in the lattice. It features planar Co centers.[6] Salcomine is both a Lewis acid and a reductant. Several solvated derivatives bind O2 to give derivatives of the type (μ-O2)[Co(salen)py]2 and [Co(salen)py(O2)].[3]
The 1938 report that this compound reversibly bound O2[8] led to intensive research on this and related complexes for the storage or transport of oxygen. Solvated derivatives of salcomine, e.g. the chloroformate or the DMF adduct, bind 0.5 equivalent of O2:
2 Co(salen) + O2 → [Co(salen)]2O2
Salcomine catalyzes the oxidation of 2,6-disubstituted phenols by dioxygen.[9]
^ abShoichiro Yamada "Advancement in stereochemical aspects of Schiff base metal complexes" Coordination Chemistry Reviews 1999, volume 190–192, 537–555.
^Bruckner, S.; Calligaris, M.; Nardin, G.; Randaccio, L. (1969). "The Crystal Structure of the Form of N,N-Ethylenebis(salicylaldehydeiminato)cobalt(II) Inactive Towards Oxygenation". Acta Crystallographica Section B. 25 (8): 1671–1674. doi:10.1107/S0567740869004523.
^Schaefer, W. P.; Marsh, R. E. (1969). "Oxygen-Carrying Cobalt Compounds. I. Bis(salicylaldehyde)ethylenediiminecobalt(II) Monochloroformate". Acta Crystallographica Section B. 25 (9): 1675–1682. doi:10.1107/S0567740869004547.
^M. Calligaris; G. Nardin; L. Randaccio; A. Ripamonti (1970). "Structural Aspects of the Synthetic Oxygen-Carrier NN′-Ethylenebis(Salicylideneiminato)cobalt(II): Structure of the Addition Compound with Oxygen Containing Dimethylformamide". J. Chem. Soc. A: 1069. doi:10.1039/j19700001069.
