Monomeric Oxygen Adducts of N,N′-Ethylenebis(acetylacetoniminato) ligandcobalt (II). Preparation and Properties

.Abstract: A series of monomeric molecular oxygen carriers of the general formula Co(acacen)(B)O2 (acacen = (CH3C(O-)=CHC(CH3)=NCH2-)2; B = N,N-dimethylformamide, pyridine, 4-aminopyridine, 4-methylpyridine, and 4-cyanopyridine) were prepared in nonaqueous solvents. These adducts are reversibly formed in solution and are shown to be monomeric by oxygen uptake and molecular weight experiments. The equilibrium constant for the reaction in N,N-dimethylformamide was measured at —10° and found to be log Keq = 2.11 ± 0.10. Crystalline adducts were isolated and characterized by means of elemental analysis, oxygen evolution measurements, molecular weight, magnetic measurements, and electronic and infrared spectra. These oxygen adducts are formulated as monomeric octahedral complexes of low-spin cobalt(III), because epr measurements³ show that the unpaired electron is largely associated with the coordinated oxygen. © 1970, American Chemical Society. All rights reserved.

Duke Scholars

Author Alvin L. Crumbliss Chemistry