Porous crystalline metal–organic frameworks (MOFs) bearing sulfonic groups (–SO_(3)H) are receiving increasing attention as solid-state proton conductors because the –SO_(3)H group can not only enhance the proton c...Porous crystalline metal–organic frameworks (MOFs) bearing sulfonic groups (–SO_(3)H) are receiving increasing attention as solid-state proton conductors because the –SO_(3)H group can not only enhance the proton concentration, but also form hydrogen bonding networks for high proton conductivity. A large number of 1,4-phenyldicarboxylic acids or biphenyldicarboxylic acids bearing two –SO_(3)H groups have been applied for the synthesis of proton-conducting MOFs. Surprisingly, 4,4′-biphenyldicarboxylic acid bearing one –SO_(3)H group has never been explored for the construction of proton-conducting materials. Herein, we first designed and synthesized 2-sulfonyl-4,4′-biphenyldicarboxylic acid (H_(3)L). By applying this ligand to react with lanthanide salts, a series of three-dimensional MOFs, (Me_(2)NH_(2))_(2)(H_(3)O)[LnL_(2)]·8H_(2)O (Ln=Eu (1), Gd (2), Tb (3)) have been prepared. Due to the presence of the uncoordinated –SO_(3)H group and the encapsulation of high concentrations of dimethylammonium and hydronium cations in the cavity, the MOFs 1–3 show a high proton conductivity (8.83 × 10^(-3) S cm^(-1)) at 95℃ and 60% relative humidity (RH). More importantly, this high proton conductivity can be maintained over 72 hours without any significant decrease at low RH.展开更多
基金supported by the National Natural Science Foundation of China(No.21476115)the Natural Science Foundation of Jiangsu Province(No.BK20181374)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX20_1027)the Cultivation Program for the Excellent Doctoral Dissertation of Nanjing Tech University(2020-03)for financial support.
文摘Porous crystalline metal–organic frameworks (MOFs) bearing sulfonic groups (–SO_(3)H) are receiving increasing attention as solid-state proton conductors because the –SO_(3)H group can not only enhance the proton concentration, but also form hydrogen bonding networks for high proton conductivity. A large number of 1,4-phenyldicarboxylic acids or biphenyldicarboxylic acids bearing two –SO_(3)H groups have been applied for the synthesis of proton-conducting MOFs. Surprisingly, 4,4′-biphenyldicarboxylic acid bearing one –SO_(3)H group has never been explored for the construction of proton-conducting materials. Herein, we first designed and synthesized 2-sulfonyl-4,4′-biphenyldicarboxylic acid (H_(3)L). By applying this ligand to react with lanthanide salts, a series of three-dimensional MOFs, (Me_(2)NH_(2))_(2)(H_(3)O)[LnL_(2)]·8H_(2)O (Ln=Eu (1), Gd (2), Tb (3)) have been prepared. Due to the presence of the uncoordinated –SO_(3)H group and the encapsulation of high concentrations of dimethylammonium and hydronium cations in the cavity, the MOFs 1–3 show a high proton conductivity (8.83 × 10^(-3) S cm^(-1)) at 95℃ and 60% relative humidity (RH). More importantly, this high proton conductivity can be maintained over 72 hours without any significant decrease at low RH.
