Abstract
A new threefold interpenetrated pillared-layer microporous metal-organic framework, [Zn-2(cca)2(4-bpdb)](n)center dot(DMF)(2n) (UTSA-85) (H(2)cca=4-carboxycinnamic acid, 4-bpdb=1,4-bis(4-pyridyl)- 2,3-diaza-1,3-butadiene, and DMF=N,N-dimethylformamide), has been designed and generated by the solvothermal reaction of mixed ligands (H(2)cca and 4-bpdb) and Zn(NO3)2.6H(2)O. Single-crystal XRD analysis disclosed that discrete paddle-wheel Zn-2(COO)(4) clusters as secondary building units linked the cca ligands to give two-dimensional layers, which were further pillared by 4-bpdb ligands to form a threefold interpenetrated pillared-layer structure. The desolvated framework, UTSA-85 a, was revealed to exhibit permanent porosity with a BET surface area of 558 m(2)g(-1) and a high selectivity of 64 for C2H2/CH4 separation at 296 K owing to the microporous (approximate to 5.0 angstrom) structure and functional azine groups that decorated the pore channels.