Two porous Co(ii) bithiophenedicarboxylate metal–organic frameworks: from a self-interpenetrating framework to a two-fold interpenetrating α-Po topological network

Abstract

Two new porous metal–organic frameworks with the formulas [Co(btdc)(bpp)(H₂O)_0.5]·8H₂O (1) and Co₂(btdc)₂(bpe)₂·19H₂O (2) (H₂btdc = 2,2′-bithiophene-5,5′-dicarboxylic acid, bpp = 1,3-di(4-pyridyl)propane, bpe = 1,2-bis(4-pyridinyl)ethane) have been synthesized under solvothermal conditions and characterized by single crystal X-ray diffraction analysis and powder X-ray diffraction, elemental analysis, IR, and thermogravimetric analysis (TGA). 1 features a three-dimensional (3D) self-interpenetrating framework which results from three-fold interpenetrating diamond network linked by the bpp ligands. 2 exhibits a three-dimensional two-fold interpenetrating pillar-layered framework with α-Po topology. The magnetic study of 1 shows that there exist antiferromagnetic interactions between the Co(II) centres.