Selective anion sensing by a ruthenium(ii)–bipyridyl-functionalized tripodal tris(urea) receptor
作者:Yongjing Hao、Peiju Yang、Shaoguang Li、Xiaojuan Huang、Xiao-Juan Yang、Biao Wu
DOI:10.1039/c2dt12488b
日期:——
A tripodal tris(urea) ligand with 2,2â²-bipyridyl (bpy) substituents (L) has been designed and synthesized, which coordinates with three equivalents of Ru(bpy)2Cl2·2H2O, followed by treatment with NH4PF6, to afford the anion receptor [(bpy)6Ru3L](PF6)6 (1). The anion-binding behavior of the ligand L and the RuIIâbpy functionalized receptor 1 toward different anions was investigated by 1H NMR (for L and 1), fluorescence, and UV-vis spectroscopy (for 1). Both compounds showed selective recognition of SO42â or H2PO4â ions in the 1â:â1 binding mode in the NMR studies. The RuII complex 1 displayed the metal-to-ligand charge transfer emission at 600 nm, which was quenched on addition of the sulfate and dihydrogen phosphate ions. Quantitative fluorescence titration experiments were carried out and the stability constants (log K) of the complex 1 with SO42â and H2PO4â ions were obtained to be 4.73 and 4.69 Mâ1 (1â:â1 binding mode), respectively.
我们设计并合成了一种具有 2,2â²-联吡啶(bpy)取代基(L)的三元三(脲)配体,它与三当量的 Ru(bpy)2Cl2Â-2H2O 配位,然后用 NH4PF6 处理,得到阴离子受体 [(bpy)6Ru3L](PF6)6(1)。通过 1H NMR(L 和 1)、荧光和紫外-可见光谱(1),研究了配体 L 和 RuIIâbpy 功能化受体 1 对不同阴离子的阴离子结合行为。在核磁共振研究中,这两种化合物都以 1:1 的结合模式选择性地识别 SO42â 或 H2PO4â 离子。RuII 复合物 1 在 600 纳米波长处显示出金属-配体电荷转移发射,这种发射在加入硫酸根离子和磷酸二氢根离子后被淬灭。通过荧光定量滴定实验得出,复合物 1 与 SO42â 和 H2PO4â 离子的稳定常数(log K)分别为 4.73 和 4.69 Mâ1 (1â:â1 结合模式)。