Two Cu(II) coordination polymers with single- and double-zigzag chains constructed from 4,4′-(dihydroxymethylene)dibenzoic acid

• Two Cu(II) coordination polymers were synthesized with a new semi-rigid V-type dicarboxylate ligand with hydroxyl groups.
• Complexes 1 and 2 display double- and single-zigzag chain structures, respectively.
• The framework of 1 possesses one-dimensional rhombic channels.
• Complexes 1 and 2 exhibit moderate thermal stabilities.

Two intriguing one-dimensional coordination polymers, [Cu2(dhmdb)2(H2O)2]⋅6H2O (1) and Cu(dhmdb)(1,10-phen) (2), have been hydrothermally synthesized and structurally characterized through exploring a new semi-rigid V-type dicarboxylate ligand with hydroxyl groups, 4,4′-(dihydroxymethylene)dibenzoic acid (H2dhmdb). Complexes 1 and 2 display double- and single-zigzag chain structures, respectively, which further result in two-dimensional supramolecular networks by O–H⋯O hydrogen-bonds and π⋯π stacking interactions. The network of 1 possesses one-dimensional rhombic channels along c axis with the size of about 8 × 8 Å. The phase purity and thermal stability of 1 and 2 have also been investigated.