Structural Diversity in Metal−Organic Frameworks Built from Rigid Tetrahedral [Si(p-C6H4CO2)4]4− Struts

The silicon-based connector [Si(p-C6H4CO2)4]4− (L) has been employed in the construction of six new metal−organic framework (MOF) materials, all of which have been characterized by single crystal X-ray diffraction techniques. The isostructural frameworks [Cd2(L)(H2O)2]·(DMA) and [Mn2(L)(H2O)2]·(DMA)2.5, IMP-8Cd and IMP-8Mn, respectively, contain extended [M(CO2)2]n chains, often termed rod SBUs (secondary building units), which are cross-linked into a 3D network by tetrahedral L struts to give microporous networks. In contrast, [Cu2(L)(H2O)2]·(DMA)12 (IMP-9) contains dinuclear paddle-wheel Cu2(CO2)4 SBUs connected together with L struts to give an overall PtS type net. [Me2NH2]2[Cd3(L)2(H2O)2]·(DMA)8(H2O)8, [Me2NH2]2[Zn3(L)2]·(DMF)6, and [Me2NH2]2[Zn3(L)2]·(DMF)3 (IMP-10, IMP-11, and IMP-12, respectively) all contain anionic 3D frameworks which are charge balanced by the presence of dimethylammonium cations within their pores. These dimethylammonium cations arise from the hydrolysis of DMA or DMF, or they...