Novel (3,4,6)-Connected Metal–Organic Framework with High Stability and Gas-Uptake Capability

A microporous and noninterpenetrated metal–organic
framework
[Cu3(L)2(DABCO)­(H2O)]·15H2O·9DMF (1) has been synthesized using two
different ligands, [1,1′:3′,1″-terphenyl]-4,4″,5′-tricarboxylic
acid (H3L) and 1,4-diazabicyclo[2.2.2]­octane (DABCO). As
revealed by variable-temperature powder X-ray diffraction (VT-PXRD)
measurements, N,N′-ditopic
DABCO plays an important role for stabilization of the Cu–L
framework. The three-dimensional framework of 1 exhibits
high stability and excellent adsorption capacity for H2 (54.3 mg g–1 at 77 K and 20 bar), CO2 (871 mg g–1 at 298 K and 20 bar), CH4 (116.7 mg g–1, 99 cm3 (STP) cm–3 at 298 K and 20 bar), and n-pentane
(686 mg g–1 at 298 K and 1 bar). Interestingly,
the excellent selectivity toward CO2 over N2 at ambient temperature (273 and 298 K) and 1 bar makes complex 1 possess practical application in gas separation and purification.