A stable zinc-4-carboxypyrazole framework with high uptake and selectivity of light hydrocarbons.

A special organic ligand, 4-carboxypyrazole (4-cpz), is chosen to synthesize a highly stable metal-organic framework (MOF) for selective sorption of light hydrocarbons. The new MOF, (H(3)O)[Zn(3)(OH)(4-cpz)3]·2(DEF)·H(2)O (FIR-51, DEF = N,N-diethylformamide), was synthesized solvothermally and shows unusual chemical stability. This compound exhibits high storage capacity for light hydrocarbons and high selectivity for C3 and C2 over methane at 273 and 294 K.