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), Cu 2 (ABTC)(H 2 O) 2 ·(DMF) 2 (H 2 O) (JUC-62), Cd 2 (ABTC)(DMF) 3 ·(DMF) 2 (JUC-63), and Mn(H 2 ABTC)(DMF) 2 (JUC-64) (H 4 ABTC = 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 H 4 ABTC 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 ABTC 4− units with 4-connected square paddle-wheel Cu 2 (CO 2 ) 4 (H 2 O) 2 secondary building units (SBUs), tetrahedral bimetallic Cd 2 (CO 2 ) 4 (DMF) 3 SBUs, and tetrahedral monometallic Mn(CO 2 ) 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.