Syntheses of new topology BTTB-based metal–organic frameworks in CH3CN/H2O mixed solvents
Three complexes, [Zn2(BTTB)](H2O)5 [BTTB = 4,4′,4″,4′″-benzene-1,2,4,5-tetrayltetrabenzoate, also named 1,2,4,5-tetrakis(carboxyphenyl) benzene] (1), [Cd2(BTTB)(H2O)5](H2O)3 (2) and [Mn2(BTTB)(H2O)5](H2O)2 (3), have been synthesized under hydrothermal conditions in CH3CN/H2O. Structural analyses revealed that 1 has new topologies, i.e. nnu1 (nnu stands for Nanjing Normal University) or nnu2 depending on the different simplification schemes. Compounds 2 and 3 are isostructural and have a scu (square planar and cubical vertices) topology, which have not been reported for BTTB-based metal–organic frameworks. Thermal stability of 1–3, hydrogen adsorption/desorption properties of 2 and 3, and luminescent properties of 1 and 2 were investigated. Compounds 1–3 are stable in air.