Structure, Hydrogen Storage, and Luminescence Properties of Three 3D Metal−Organic Frameworks with NbO and PtS Topologies

Three 3D multifunctional microporous metal−organic frameworks (MOFs), Cu2(ABTC)(H2O)2·(DMF)2(H2O) (JUC-62), Cd2(ABTC)(DMF)3·(DMF)2 (JUC-63), and Mn(H2ABTC)(DMF)2 (JUC-64) (H4ABTC = 3,3′,5,5′-azobenzenetetracarboxylic acid, DMF = N,N′-dimethylformamide, and JUC = Jilin University China) have been synthesized by self-assembly of a rigid tetra-carboxylate ligand H4ABTC and corresponding transition metal salts under mild conditions. X-ray crystallography reveals that their topologies are based on NbO (JUC-62) and PtS (JUC-63 and JUC-64) nets, constructed of 4-connected rectangular ABTC4− units with 4-connected square paddle-wheel Cu2(CO2)4(H2O)2 secondary building units (SBUs), tetrahedral bimetallic Cd2(CO2)4(DMF)3 SBUs, and tetrahedral monometallic Mn(CO2)4(DMF)3 SBUs, respectively. High-pressure hydrogen sorption of the activated JUC-62 reveals a type I profile at 77 K, which is saturated at 40 bar with a hydrogen uptake of about 4.71 wt%. Photoluminescence investigations reveal that JUC-62 and JUC-63 display strong main emission spectra peaks at 392 and 402 nm, respectively.