The binding tendencies of the enantiomeric forms, R,R and S,S, of the neutral receptor 1 towards anions were investigated through UV-vis and 1H NMR titration experiments in DMSO. Both enantiomers form stable H-bond complexes with carboxylates and phosphates. In particular, receptor 1 strongly binds two H2PO4- ions according two stepwise equilibria, in which logK2 is higher than logK1. Such an unusual
通过在DMSO中的UV-vis和1H NMR滴定实验研究了中性受体1的对映体形式R,R和S,S与阴离子的结合趋势。两种对映异构体均与羧酸盐和磷酸盐形成稳定的H键络合物。特别地,受体1根据两个逐步平衡而牢固地结合两个H 2 PO 4-离子,其中logK2高于logK1。这种异常的协同作用效应归因于当与受体的两个尿素亚基结合时,两个H2PO4-阴离子之间形成强的H键相互作用,如1:2配合物的晶体和分子结构所证明的盐:[Bu4N] 2 [R,R-1 ...(H2PO4)2]。S,S对映异构体与生物学上相关的D-2,3-二磷酸甘油酸根阴离子形成H键络合物,其缔合常数是R,R络合物的缔合常数的两倍。
A simple thiourea based colorimetric sensor for cyanide anion
作者:Maurice O. Odago、Diane M. Colabello、Alistair J. Lees
DOI:10.1016/j.tet.2010.07.006
日期:2010.9
A simple and easily synthesized colorimetric anion sensor, based on a thiourea moiety as a binding subunit on a 1,2-cyclohexane backbone and a p-nitrophenyl group as a signaling unit, has been synthesized in a one step procedure. The selective sensing of anions, particularly cyanide, has been investigated in DMSO by UV-vis titration, (1)H NMR titration techniques and through 'naked eye' observation experiments. (C) 2010 Elsevier Ltd. All rights reserved.