Synthesis, Structure, and Gas Sorption Studies of a Three-Dimensional Metal−Organic Framework with NbO Topology

Abstract

A new tetracarboxylate ligand with two alkyne functionalities has been synthesized and used to form a three-dimensional (3D) metal−organic framework {[Cu2(BDDC)(H2O)2]·DMF·3H2O}n (H4BDDC = 5,5′-(buta-diyne-1,4-diyl) diisophthalic acid) (DMF = N,N′-dimethylformamide). The single-crystal structure analysis reveals the topology is based on the NbO net, constructed by 4-connected rectangular ligands and 4-connected square Cu2(CO2)4 secondary building units (SBUs). The compound has permanent porosity with a large Langmuir surface area of 3111 m2/g, and shows excess and total H2 uptake as high as 3.98 and 4.60 wt %, respectively, at 77 K and 17 bar.