Construction of 3D supramolecular networks based on 1D chains from flexible bis(imidazolyl) and 4-hydroxybenzolate

The reaction of 1,2-bis(imidazol-1′-yl)ethane (bime), 4-hydroxybenzoic acid (HO-HBC) with different metal salts in water/ethanol gave rise to three supramolecular architectures [M(HO-BC)2(H2O)2(bime)]n [M = Mn(II), Co(II) and Ni(II)]. Single crystal X-ray diffraction analysis reveals that complexes 1–3 are isomorphous and are 3D supramolecular networks. HO-BC serves as a monodentate ligand through one carboxylate oxygen atom coordinating to metal center. The extensive hydrogen bonds from HO-BC and coordination water result in the formation of 3D supramolecular networks. The gauche-conformational bime connects the neighboring metal ions into 1D chain, which is located in the large void of the 3D networks. The thermogravimetric analysis reveals that complexes 1–3 are stable before 273 °C. Magnetic analysis shows that there are no interactions between neighboring metal ions.