A new microporous metal-organic framework with open metal sites and exposed carboxylic acid groups for selective separation of CO2/CH4 and C2H2/CH4

A new microporous metal-organic framework Cu-6(DDCBA)(3) (ZJU-72, H(5)DDCBA = 3,5-di(3',5'-dicarboxylpheny)-benozoic acid) with open metal sites and exposed carboxylate groups is rationally designed and synthesized, exhibiting a low binding energy of 9.7 kJ mol(-1) for C2H2 and 15.1 kJ mol(-1) for CO2 and a high separation selectivity of 39.7 for C2H2/CH4 at 298 K and 8.2 for CO2/CH4 at 273 K.