A novel ONO-type bis-tridentate ligand L1 was synthesized by a diazocoupling reaction of 3,3'-dihydroxybenzidine with 6-octyl-2-naphthol in 58% yield. Azo-hydrazo tautomerization in Li was indicated by the NWIR and IR spectra. The 1:1 complexation of Li and Mn(III) or Co(II) ions was confirmed by titration experiments at room temperature. Mn-, Co-, and Cr-based metallo-supramolecular polymers were prepared via the 1:1 complexation of the ditopic ligand with the metal ions at 100 degrees C. The Mn- and Cr-based polymers exhibited reversible redox properties.