Three Unprecedented Entangled Metal−Organic Frameworks: Self-Penetration and Hydrothermal in Situ Ligand Formation

Three unprecedented entangled systems are successfully obtained. Compounds 1 and 2 are self-penetrating networks with intracatenated [M₂bimh₂] loops and two-dimensional [M₂(bptc)] sheets ((H₄bptc = biphenyl-3,3′,4,4′-tetracarboxylic acid, bimh = 1,6-bis(imidazol-1-yl)-hexane), while compound 3 is a three-dimensional self-penetrating network which results from the hydrothermal in situ formation of a new tetradentate ligand, 1,2,4,5-tetra(4-pyridyl)benzene, through dehydrogenative coupling of 1,3-bis(4-pyridyl)propane molecules.