Reaction duration-dependent formation of two Cu(II)-MOFs with selective adsorption properties of C3H4 over C3H6

摘要: The formation of metal–organic frameworks (MOFs) under given reaction conditions depends on various factors including duration, temperature, used solvent, system pH, and others. Among them, the duration is relatively less investigated. In this work, based a Cu(II)-MOF system, was found to play an important role in directing two different products, (NH2(CH3)2)[Cu12(DDPN)6(H2O)10Cl] (BUT-301) shorter time (NH2(CH3)2)2[Cu(DDPN)] (BUT-302) longer time, when CuCl2 reacted with 3,5-di(3,5-dicarboxylphenyl)nitrobenzene (H4DDPN) DMA/MeOH mixed solvent at 120 °C. With increasing BUT-301 can transform into BUT-302. Both MOFs have three-dimensional (3D) framework structures. constructed from paddle-wheel Cu2(COO)4 units DDPN4– ligands as four-connected linkers, while BUT-302 assembled mononuclear Cu(II) centers connecting also linkers but monodentate coordination fashion. N2 adsorption confirmed that both are porous materials Brunauer–Emmett–Teller (BET) surface areas 1953 561 m2 g−1, respectively. Interestingly, -302 show selective properties C3H4 over C3H6. C3H4/C3H6 selectivities were calculated be 1.9 4.4 0.1 bar 298 K by ideal adsorbed solution theory (IAST) for 1 : 99 mixture,