A One-Dimensional Double-Chain Co(II) Metal–Organic Framework Based on Mixed Flexible N-donor Carboxylate and Bipyridine Ligands: Synthesis, Structure, Thermal Stability and Magnetic Property

Abstract

A new metal–organic framework (MOF), [Co(L)2(4,4′-bipy)]n (1) [HL = 4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoic acid, 4,4′-bipy = 4,4′-bipyridine], has been solvothermally synthesized and characterized by single crystal X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis, and powder X-ray diffraction. As revealed by the single crystal X-ray diffraction, there exist two kinds of the L− ligands that are “Z”-shaped and “U”-shaped L− ligands in complex 1. Two “U”-shaped L− ligands bridge two symmetry-related Co(II) cations to form a dinuclear [Co2(COO)2] secondary building unit (SBU). The adjacent dinuclear SBUs are connected by bipillared 4,4′-bipy ligands to generate an interesting one-dimensional double chain, which is further consolidated by the intrachain π–π interactions between neighbouring pyridyl rings of 4,4′-bipy ligands. These one-dimensional double chains are further linked by multiple interchain C–H···N, C–H···π and π–π weak interactions to form a three-dimensional supramolecular architecture. Thermogravimetric analysis and variable-temperature powder X-ray diffraction studies indicate that complex 1 shows good thermal stability. In addition, the magnetic investigation reveals that complex 1 exhibits an antiferromagnetic interaction between two Co(II) ions in the dinuclear [Co2(COO)2] SBU. A one-dimensional double-chain Co(II) (MOF), [Co(L)2(4,4′-bipy)]n (1) [HL = 4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoic acid, 4,4′-bipy = 4,4′-bipyridine], has been solvothermally synthesized and characterized. The thermal stability and magnetic property of 1 have been investigated.