Stereochemistry of Cobalt(III) Complexes Containing (N,O)-Five and Six-membered Aminoalcohol Chelate Rings

⁵⁹Cq NMR (94.45 MHz) has been used to study Co^III complexes formed by reaction of cobalt(II) chloride with 2- and 3-aminoalcohols; mononuclear molecular tris-O,N-chelate complexes of Co^IIIL₃ (L = NH₂CH₂CH₂O^– and NH₂CH₂CH₂CH₂O^–) are produced in both geometric mer- and fac-forms, the mer-isomers being thermodynamically unstable and spontaneously rearranging to the fac-form in solution; the analogous complex L = NH₂CHEtCH₂O^– exists only in the fac-form; 2-aminoalcohols also yield trinuclear complexes [Co^II(Co^IIIL₃)₂]²⁺, in which pseudo-contact interaction of the Co^II and Co^III atoms occurs; the crystal structure of {Co^II[Co^III(NH₂CH₂CH₂O)₃]₂}·Cl₃(NH₃CH₂CH₂OH)·2H₂O has been determined.