Anion binding to a ferric porphyrin complexed with per-O-methylated β-cyclodextrin in aqueous solution
Anion binding to a ferric porphyrin complexed with per-O-methylated β-cyclodextrin in aqueous solution
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DOI：
10.1021/ja045472i
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发表时间：
2004-11-24
影响因子：
15
通讯作者：
Yamada, A
中科院分区：
文献类型：
--
作者：
Kano, K;Kitagishi, H;Yamada, A
5,10,15,20 - 四（4 - 磺酸钠苯基）卟啉铁（III）（Fe(III)TPPS）与七（2,3,6 - 三 - O - 甲基）-β - 环糊精（TMe - β - CD）形成一种非常稳定的1∶2配合物，其铁（III）中心位于由两个面对面的TMe - β - CD分子形成的疏水裂缝中。各种无机阴离子（X⁻）如F⁻、Cl⁻、Br⁻、I⁻、N₃⁻和SCN⁻与Fe(III)TPPS(TMe - β - CD)₂配位形成五配位的高自旋Fe(III)TPPS(X)(TMe - β - CD)₂，而ClO₄⁻、H₂PO₄⁻、NO₃⁻和HSO₄⁻不发生配位。除F⁻外，在没有TMe - β - CD的情况下，由于阴离子以及Fe(III)TPPS的广泛水合作用，所研究的阴离子都不会与Fe(III)TPPS配位。本体系对N₃⁻阴离子表现出高选择性。热力学表明，X⁻阴离子的路易斯碱性、亲水性和形状是决定Fe(III)TPPS(X)(TMe - β - CD)₂配合物稳定性的主要因素。
5,10,15,20-Tetrakis(4-sulfonatophenyl)porphinato iron(Ill) (Fe(III)TPPS) forms a very stable 1:2 complex with heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TMe-beta-CD), whose iron(Ill) center is located at a hydrophobic cleft formed by two face-to-face TMe-beta-CD molecules. Various inorganic anions (X-) such as F-, Cl-, Br-, I-, N-3(-), and SCN- coordinate to Fe(III)TPPS(TMe-beta-CD)(2) to form five-coordinate high-spin Fe(III)TPPS(X)(TMe-beta-CD)(2), while no coordination occurs with ClO4-, H2PO4-, NO3-, and HSO4-. Except for F-, none of the anions investigated coordinate to Fe(III)TPPS in the absence of TMe-beta-CD due to extensive hydration to the anions as well as to Fe(III)TPPS. The present system shows a high selectivity toward the N-3(-) anion. The thermodynamics suggests that Lewis basicity, hydrophilicity, and shape of an X- anion are the main factors to determine the stability of the Fe(III)TPPS(X)(TMe-beta-CD)(2) complex.