The reaction of cobalt(II) pivalate with a spin-labeled Schiff base (HL(1)) in organic solvents formed trinuclear complex [Co3(Piv)2L(1)2L(2)2]·Solv (Solv is Me2CO and/or C7H16 and CH3CN) containing both nitroxide L(1) and the product of its single-electron reduction, nitrone L(2). The formation of [Co3(Piv)2L(1)2L(2)2] was a consequence of an unusual phenomenon, which we called "redox-induced change in the ligand coordination mode". A reduction of L(1) to L(2) led to a change in the set of donor atoms and even in the size of the metallocycle. This phenomenon was also found for mononuclear [CrL(1)2L(2)] and [FeL(1)2L(2)]·Me2CO.