Synthesis Of Benzimidazoles And The Ions Recognition Properties

This paper includes four chapters:Chapter One: This one is about the research of recognition in recent years.Including three parts:(Ⅰ) research anions recognition;(Ⅱ) research cationsrecognition;(Ⅲ) the research status and the progress of the Synthesis ofbenzimidazoles and cations recognition;Chapter Two: a novel selective sensor M based on1,4-bis (2-benzimidazolyl) benzenehas been designed and prepared. Sensor M behaves a single selectivity and sensitivityin the recognition for Hg2+over other metal ions such as Fe3+, Hg2+, Ag+, Ca2+, Zn2+,Pb2+, Cd2+, Ni2+, Co2+, Cr3+,Mg2+and F-，Cl-，Br-，I-，AcO-， HSO4-，ClO4-，SCN-，CN-，H2PO4-in DMSO. When adding Hg2+to M of DMSO, receptor moleculessolution fluorescence immediately changed from light blue color to dark blue, andother cation has no obvious change, realizing the effect on the detection of Hg2+.Fluorescence titration data show that fluorescence intensity gradually increased andredshift with the increase of Hg2+concentration. The limits of detection concentration(LDC) of M receptor molecules for Hg2+is5.579×10-6mol/L.In the middle of theanion, receptor molecule M has single selective recognition for F-. When adding F-to M in DMSO, receptor molecules solution fluorescence immediately changed fromlight blue colored to dark blue, and other anion without this change, so realizing thedetection effect of F-. Fluorescence titration data show that main body gradually withthe increase of the concentration of F-fluorescence enhancement and redshift.Receptor molecules M to F-the minimum detection limit is8.543×10-6mol/L.Chapter Three: Another2,2′-bisbenzimidazole was synthesized and the receptormolecules L, which has the single selective recognition for Fe3+.When adding Fe3+to L in DMSO, the fluorescence quench, but other anion has no this change, sorealizing the detection effect of Fe3+. Fluorescence titration data show that thefluorescence intensity of L gradually reduced with the increase concentration of Fe3+.The detection limit of receptor molecules to Fe3+is7.109×10-8mol/L.