自组装[Pd6(L)4]8+型大环配合物用于荧光传感HSO3-

在本研究中，通过金属定向的分级自组装反应，以芳基吡唑-吡啶配体与双金属钯组装子在水溶液中合成了平行四边形的大环超分子金属环[Pd₆(bpy)₆(L¹)₄](PF₆)₈ (1a)和[Pd₆(bpy)₆(L²)₄](PF₆)₈ (2a)，其中 HL¹=1-(1H-pyrazole-4-yl)-4-(4-pyridyl)benzene，HL²=9-(1H-pyrazole-4-yl)-10-(4-pyridyl)anthracene，bpy=2，2''-联吡啶。通过单晶X射线衍射证实了超分子钯平行四边形的结构。值得注意的是，这2个平行四边形金属环可以用作开启型荧光传感器，通过拆卸机制检测HSO₃^-。此外，基于配合物1a的传感器显示出对HSO₃^-的选择性检测，不受其他阴离子的干扰。检测限低至0.131 μmol·L^-1。此外，配合物1a还通过荧光变化实现了在试纸模式下对HSO₃^-的半定量可视化检测。

Self-assembly of [Pd6(L)4]8+-type macrocyclic complexes for fluorescent sensing of HSO3-

In this study, parallelogram-like macrocyclic supramolecular metallacycles [Pd₆(bpy)₆(L¹)₄](PF₆)₈ (1a) and [Pd₆(bpy)₆(L²)₄](PF₆)₈ (2a), where HL¹=1-(1H-pyrazole-4-yl)-4-(4-pyridyl)benzene, HL²=9-(1H-pyrazole-4-yl)-10-(4-pyridyl)anthracene，and bpy=2,2''-bipyridine, are synthesized by reacting aryl pyrazole pyridine ligands with dipalla-dium corners in aqueous solutions via metal-directed hierarchical self-assembly. The structures of the supramolecular Pd parallelograms are confirmed through single-crystal X-ray diffraction. Notably, the two parallelogram metallacycles can be used as“turn-on”fluorescence sensors to detect HSO₃^- through a disassembly mechanism. In addition, the 1a-based sensor shows selective detection of HSO₃^- without interference from other anions. The detection limit was as low as 0.131 μmol·L^-1. Furthermore, complex 1a presented the semiquantitative visual detection ability for HSO₃^- in the test trip mode via fluorescence changes.