A microporous metal-organic framework of sql topology for C2H2/CO2 separation

A new two-dimensional (2D) microporous metal-organic framework, [Cu(BDC-2Br)(H2O)]center dot DMF (UTSA-83, DMF = N,N'-dimethylformamide), has been synthesized by solvothermal reaction of 4,6-dibromoisophthalic acid (H2BDC-2Br) and Cu(NO3)(2)center dot 2.5H(2)O. Single-crystal X-ray crystallographic study reveals that the Cu(II) atoms in UTSA-83 are linked by BDC-2Br ligands to form square grid-like (sql) layers, further stacking together via multiple hydrogen bonding interactions. The removal of DMF molecules allows UTSA-83a to exhibit permanent porosity. Gas sorption measurements of UTSA-83 exhibited selective acetylene (C2H2) adsorption over carbon dioxide (CO2) with a C2H2/CO2 uptake ratio of about 3.1 at 298 K and 1 atm, giving a C2H2/CO2 selectivity of 6.2.