Three New Complexes Based on a Flexible Bis(benzimidazole) Ligand and Rigid/Flexible Organic Carboxylates

Abstract

Three new polymeric frameworks, [Ni(bbbm)(L1)2] n (1), [Ni(bbbm)(L2)2] n (2), and {[Co(bbbm)(L3)]·H2O} n (3) (bbbm = 1,4-bis(N-benzimidazolyl) butane, HL1 = 4-bromobenzoic acid, HL2 = 3-methylbenzoic acid, and H2L3 = glutaric acid) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 features a one-dimensional (1D) linear chain structure bridged by bbbm ligands, which is further connected into a supramolecular double chain structure through intermolecular π–π stacking interactions. Complex 2 contains 1D zigzag chain, which is further arranged into a 2D supramolecular architecture by hydrogen bonding and π–π stacking interactions. In the structure of 3, there are infinite 1D zigzag Co(II)-bbbm chains linked together by L3 ligands to generate an undulated 2D (4,4) sheet, which is further connected by intermolecular π–π stacking interactions to form a 3D supramolecular network. Furthermore, thermal stability and luminescent property of 1–3 were investigated. Three new two/three-dimensional supramolecular complexes [Ni(bbbm)(L1)2] n (1), [Ni(bbbm)(L2)2] n (2), and {[Co(bbbm)(L3)]·H2O} n (3) [bbbm = 1,4-bis(N-benzimidazolyl) butane] have been synthesized from hydrothermal reaction of a metal salt with ligands: bbbm and one carboxylate ligand, 4-bromobenzoic acid (HL1), 3-methylbenzoic (HL2), and glutaric acid (H2L3).