Preparation of N -heterocyclic carbene dinuclear silver macrometallocycle and the recognition performance for iodide ion

An N-heterocyclic carbene (NHC) dinuclear silver macrometallocycle 1 was prepared, characterised and tested for its effectiveness as an iodide ion probe. The precursor ligand, 1,3-bis(N-picolyl-benzimidazol-1-yl)propane hexafluorophosphate (LH2·(PF6)2), was prepared, characterised and used to construct macrometallocycle 1 by combining two ligands and two silver ions. The structure of 1 was determined through X-ray single crystal diffraction, 1H NMR and 13C NMR. In addition, the selective recognition performance of 1 for some anions (F−, Br−, Cl−, I−, HPO42−, H2PO4−, OAc−, HSO4− and NO3−) was investigated by fluorescence spectra, UV/VIS spectra, HRMS, 1H NMR and infrared spectra. The experimental results displayed that 1, as a fluorescence probe, can effectively distinguish iodide ions from other anions.