Adamantane bisurea derivatives: anion binding in the solution and in the solid state
Adamantane bisurea derivatives: anion binding in the solution and in the solid state
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DOI：
10.1016/j.tet.2012.11.030
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发表时间：
2013-01-14
期刊：
影响因子：
2.1
通讯作者：
Basaric, Nikola
中科院分区：
文献类型：
--
作者：
Blazek, Vesna;Molcanov, Kresimir;Basaric, Nikola
合成了含苯基(5，6)、1-萘基(7，8)和9-芳基(9)荧光团的1，3-二(3-芳基脲)金刚烷受体。用紫外-可见光谱和荧光分光光度法研究了它们与溶液中F-、Cl-、Br-、OAc-、NO3-、HSO4-和H2PO4-的络合能力。与含有柔性间隔基(含丙烯或戊二烯，2和4)和刚性金刚烷类似物(1和3)的2-萘基双脲类化合物的结合进行了比较。在溶液中，受体与除NO3-以外的所有阴离子形成稳定的络合物。在CH3CN中络合能力与阴离子的碱性和尿素N-H的酸度有关，而在DMSO中络合物的稳定性变化不大。受体1的X射线结构表明，金刚烷部分的掺入使受体以镊子状构象预先组织起来，以形成最佳的氢键网络和对H_2PO_4-阴离子的高选择性。金刚烷和尿素之间的亚甲基间隔物的引入还增加了与阴离子的络合物的稳定性。对如下配合物进行了X射线结构分析：1中心点Bu4NH_2PO_4，3中心点Bu4NH_2PO_4，5中心点Bu4NH_2PO_4中心点4H(2)O，5中心点Bu4NOAc中心点H_3H(2)O。H_2PO_4-氢键，对于识别阴离子是必不可少的，以及H_2PO_4-.H_2O_4-氢键。(C)2012爱思唯尔有限公司。保留所有权利。
1,3-Bis-(3-arylureido)adamantane receptors, bearing phenyl (5,6), 1-naphthyl (7,8) and 9-anthryl (9) fluorophore, were synthesized. Their ability for complexation with F-, Cl-, Br-, OAc-, NO3-, HSO4-, and H2PO4- in solution was investigated by UV-vis and fluorescence spectrophotometry. The binding was compared to that of 2-naphthyl bisurea derivatives with flexible spacers (bearing propylene or pentalene, 2 and 4) and rigid adamantane analogues (1 and 3). In solution, the receptors form stable complexes with all anions except with NO3-. The complexation ability in CH3CN correlates with the basicity of anion and the acidity of the urea N-H, whereas in DMSO the complexes stability variations are less pronounced. The X-ray structure of receptor 1 indicates that incorporation of the adamantane moiety preorganizes the receptor in a tweezer-like conformation for the optimal formation of hydrogen bonding network and high selectivity for H2PO4- anion. Incorporation of the methylene spacers between the adamantane and the urea additionally increases stability of the complexes with anions. X-ray structural analysis was performed on the following complexes: 1 center dot Bu4NH2PO4, 3 center dot Bu4NH2PO4, 5 center dot Bu4NH2PO4 center dot 4H(2)O, and 5 center dot Bu4NOAc center dot 3H(2)O. All H2PO4- complexes include extensive receptor ... H2PO4- hydrogen bonds, essential for the anion recognition, as well as H2PO4- ... H2PO4- hydrogen bonds. (c) 2012 Elsevier Ltd. All rights reserved.