The reactivity of 1,5-diisopropyl-3-(4′-carboxyphenyl)-6-oxoverdazyl HI_i-Pr toward divalent metal ions is dominated by the coordination of the carboxylate moiety onto the metal ions. The formula of the compound obtained by the reaction with the earth-alkaline magnesium (II) is [Mg(I_i-Pr)₂·2H₂O]_n·0.35H₂O (I_i-Pr–Mg) whereas the reaction with 3d divalent metal ions yields compounds of general formula [M(I_i-Pr)₂(CH₃OH)₄] (M = Mn (I_i-Pr–Mn), Co (I_i-Pr–Co), Ni (I_i-Pr–Ni), Zn (I_i-Pr–Zn)). The single-crystal X-ray diffraction analysis of I_i-Pr–Mg reveals that the magnesium (II) adduct forms a one-dimensional (1D) coordination polymer with a terminal radical in a bidentate κ(O,O′) coordination mode and a bridging one in a μ − 1κ(O); 1κ (O′) syn–anti mode. The coordination sphere of the magnesium (II) is completed by two water molecules that established H-bonds with the carboxylate moiety of the terminal radicals that further reinforce the 1D coordination polymer. Adjacent chains interact through π-stacking of head-to-tail radicals. The single-crystal X-ray diffraction analysis of I_i-Pr–Mn and I_i-Pr–Ni reveals that the two compounds are isostructural. They are composed of mononuclear complexes where the divalent metal is surrounded by two radicals coordinated by monodentate carboxylate and four methanol molecules in the equatorial plane. Two methanol ligands act as H-bond donors toward the second oxygen atom of the carboxylate groups. The complexes interact through π-stacking of head-to-tail radicals and H-bonds between the two remaining methanol ligands and the oxygen atom of the oxoverdazyl moieties. In all of the compounds, the exchange interaction is dominated by the weak antiferromagnetic coupling related to the π-stacking of the radicals.