Three-Dimensional Eight- or Four-Connected Metal−Organic Frameworks Tuned by Hydrothermal Temperatures.

Two novel three-dimensional (3D) metal−organic frameworks (MOFs) with cobalt(II) clusters as nodes and mixed bridging ligands as links, Co4(OH)2(obbz)3(4,4‘-bpy)2(4,4‘-bpy) (obbz2-N,N‘-oxamidobis(benzoato), 4,4‘-bpy 4,4‘-bipyridine) (1) and Co3(H2O)(obbz)3(4,4‘-bpy)2(H2O)2(2), were obtained from the same reaction mixture but tuned by different hydrothermal temperatures:  the 160 °C product 1is a 3D MOF based on the novel tetranuclear cluster node Co4(OH)26, displaying a new eight-connected 364145464topology, whereas the 140 °C product 2is a 2-fold interpenetrating 3D MOF constructed from not only the binuclear cluster node Co2(2-H2O)4but also the mononuclear node Co2, showing a distorted diamond network. [ABSTRACT FROM AUTHOR]