Synthesis And Properties Of PH Sensors Based On Acylhydrazones And Benzimidazoles

This paper includes four chapters:Chapter1: Research progress of pH sensorLiteratures of pH sensors in recent years were reviewed, the status and progress ofrelated studies were described. Different from the pH sensing mechanism of pHsensor, divided into three categories “deprotonation and protonation” model;“pHchange induced special reactions (such as hydrolysis, esterification reactions and soon)” model;“pH induced the aggregation of nanoclusters” model. On the basis ofliterature review, we presented the research program of this paper.Chapter2: Synthesis and properties of pH sensors based on acylhydrazonespH sensors L1-L3based on nitrophenyl furoyl hydrazone were designed andsynthesized, with dual output modes of sensor L1according to a specific pH changein a very narrow range (pH=12.0-12.5, only0.5pH unit), and the response processeswouldn't be interfered with common anions or cations. Sensor L1can perform as notonly a highly reversible “ON-OFF-ON” molecular switch accurately controlled by pHchanges but also an IMP function logic gate.Chapter3: Synthesis and properties of pH sensors based on nitrophenyl furylbenzimidazolespH sensors L4-L5based on nitrophenyl furyl benzimidazoles were designed andsynthesized, Sensor L4under basic pH conditions (pH=12.0-13.5), with dual outputmodes to detect pH, the detection processes wouldn't be interfered with commonanions or cations. Therefore, L4can act as a reversible alkaline fluorescent sensor.Chapter4: Synthesis and properties of pH sensor based on coumarinbenzimidazolepH sensor L6based on coumarinbenzimidazole was designed and synthesized. InDMSO/H2O (1:1/v: v) HEPES buffered solutions, within the range from pH=5.0to8.0, to emit strong green fluorescence, with the potential applications in the future.Furthermore, sensor L6can act as an “ON-OFF-ON” molecular switch triggered byOH-and H+ions.