10.1021/cg801026y.s001 Lu Feng Lu Feng Zhenxia Chen Zhenxia Chen Tengbiao Liao Tengbiao Liao Peng Li Peng Li Yu Jia Yu Jia Xiaofeng Liu Xiaofeng Liu Yongtai Yang Yongtai Yang Yaming Zhou Yaming Zhou Supramolecular Isomerism of Metal−Organic Frameworks Derived from a Bicarboxylate Linker with Two Distinct Binding Motifs American Chemical Society 2009 carboxylate groups framework interpenetrating Bicarboxylate Linker biphenyl connectors Supramolecular Isomerism coordination geometry Cu MOF NbO topology building units SBU tetrahedral configuration diamond topology arrangement ligand acts 2009-03-04 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Supramolecular_Isomerism_of_Metal_Organic_Frameworks_Derived_from_a_Bicarboxylate_Linker_with_Two_Distinct_Binding_Motifs/2874151 Two novel metal−organic frameworks (MOFs), Cu(3,4′-bpdc)(H<sub>2</sub>O)·DMF·2H<sub>2</sub>O (<b>1</b>) and Cu(3,4′-bpdc)(H<sub>2</sub>O)·2DMF·4.5H<sub>2</sub>O (<b>2</b>), have been solvothermally synthesized by the reaction of a unsymmetrically substituted carboxylate ligand 3,4′-biphenyldicarboxylic acid (3,4′-bpdc) and Cu(NO<sub>3</sub>)<sub>2</sub>·2.5H<sub>2</sub>O. X-ray crystal structural analyses reveal that both MOFs possess the binuclear paddle-wheel units [Cu<sub>2</sub>(O<sub>2</sub>CR)<sub>4</sub>], which are linked by the biphenyl connectors, to give two different three-dimensional (3-D) frameworks. The structural diversities are due to the different coordinated arrangements of the two distinct carboxylate groups. In <b>1</b>, the noncentral symmetrical A−A−B−B arrangement leads to an uncommon twisted Cu-paddlewheel unit, which favors a tetrahedral configuration to generate a 3-fold interpenetrating 3-D framework with a diamond topology. In <b>2</b>, the paddle-wheel unit constructed by the central symmetrical A−B−A−B arrangement of the ligand acts as a square-planar 4-connected node to give a 2-fold interpenetrating 3-D framework with an NbO topology. These two polymorphs are very rare in MOFs that exhibit similar metal local coordination geometry and the same secondary building units (SBU) but different ligands linking modes. Furthermore, both <b>1</b> and <b>2</b> possess large one-dimensional channels and show the ability to adsorb H<sub>2</sub>.