Three double- or triple-stranded chains constructed from different cobalt(II) salts and a flexible bis-triazole ligand

Abstract

Three coordination compounds, {[Co(btrp)2(H2O)2] · NO3 · H2O} n (1), {[Co(btrp)2(H2O)2] · H2O · 2H2btc} n (2), and {[Co(btrp)3] · 2ClO4} n (3) (btrp = 1,3-bis(1,2,4-triazol-1-yl)propane; H3btc = benzene-1,3,5-tricarboxylic acid), have been prepared via solvothermal method and characterized by single-crystal X-ray diffraction and elemental analyses. Compound 1 possesses a 1-D double-stranded chain composed of ribbons of 20-membered cycles. Binuclear water clusters link adjacent nitrate anions to form a 1-D supramolecular helix in the structure. Compound 2 has a 1-D double-stranded chain wherein free H2btc ligands constitute 1-D negative chains through classical hydrogen-bonding interactions (O–H ··· O). Compound 3 exhibits a triple-stranded 1-D chain. For 1–3, 3-D supramolecular structures are consolidated by interchain weak hydrogen-bonding interactions as well as electrostatic interactions.