Cationic M2L4 cages for perchlorate removal from aqueous solutions and preferential perchlorate incorporation in hydrophilic solutions
Cationic M2L4 cages for perchlorate removal from aqueous solutions and preferential perchlorate incorporation in hydrophilic solutions
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DOI：
10.1039/c6ce00267f
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发表时间：
2016-06
期刊：
影响因子：
3.1
通讯作者：
Eriko Sone;Moeko Sato;Masaru Mochizuki;Chihiro Kamio;Katsunori Yamanishi;M. Kondo
中科院分区：
文献类型：
--
作者：
Eriko Sone;Moeko Sato;Masaru Mochizuki;Chihiro Kamio;Katsunori Yamanishi;M. Kondo
合成并表征了4个新的笼型化合物[A <$Cu2（m-bbitrb）4]A3（A = Cl−（1a），Br−（1b），m-bbitrb = 1，3-双（苯并咪唑-1-基甲基）-2，4，6-三甲基苯）和[SO 4 <$Cu2（m-bbitrb）4]A2（A = Cl−（2a），Br−（2b））。这些化合物具有M2 L4型阳离子笼，在笼中掺入阴离子。虽然这四种化合物不溶于水，但它们通过与笼外的阴离子交换，表现出从水溶液中去除ClO 4 −的活性。[Cl <$Cu2（m-bbitrb）4]3+笼优先从水溶液中去除ClO 4 −。为了研究阳离子笼的选择性去除过程，通过在MeCN和MeCN/H2O溶液中获得[SO 4·Cu 2（m-bbitrb）4]（ClO 4）2（2d）的固态反射光谱、吸收光谱和ESI-TOF质谱，研究了[Cu 2（m-bbitrb）4]4+笼对ClO 4 −的亲和力。结果表明，[SO 4 <$Cu2（m-bbitrb）4]2+中的SO 42-保留在MeCN溶液中，而在MeCN/H2O溶液中，SO 42-与位于笼外的ClO 4-交换。这是因为溶液亲水性的增加促进了疏水性ClO 4-结合到疏水性笼中，这意味着从水溶液中优先去除ClO 4-是由于在固态M2 LB 4笼外产生的疏水空间的亲和力更高。
Four new cage-type compounds, [A ⊂ Cu2(m-bbitrb)4]A3 (A = Cl− (1a), Br− (1b), m-bbitrb = 1,3-bis(benzimidazol-1-ylmethyl)-2,4,6-trimethylbenzene), and [SO4 ⊂ Cu2(m-bbitrb)4]A2 (A = Cl− (2a), Br− (2b)), were synthesized and characterized. These compounds have a M2L4-type cationic cage, incorporating an anion in the cage. Although the four compounds are insoluble in water, they exhibit ClO4− removal activity from aqueous solutions by exchange with anions located outside the cage. The [Cl ⊂ Cu2(m-bbitrb)4]3+ cage removes ClO4− from aqueous solutions preferentially. To study the selective removal process by the cationic cage, the affinity of the [Cu2(m-bbitrb)4]4+ cage for ClO4− was studied by acquiring the solid-state reflectance spectra, absorption spectra, and ESI-TOF mass spectra in solutions of MeCN and MeCN/H2O for [SO4 ⊂ Cu2(m-bbitrb)4](ClO4)2 (2d). The results indicated that the SO42− in [SO4 ⊂ Cu2(m-bbitrb)4]2+ was retained in the MeCN solution, whereas in the MeCN/H2O solution the SO42− was exchanged with the ClO4− located outside the cage. This is because an increase in the hydrophilicity of the solution promotes the incorporation of hydrophobic ClO4− into the hydrophobic cage, meaning that the preferential removal of ClO4− from aqueous solutions is due to the higher affinity of the hydrophobic space created outside the M2LB4 cages in the solid state.