Preparation And Properties Of Fluorescence Sensors For Metal Ions Based On Conjugated Schiff Base

As a kind of important organic intermediates, Schiff bases are widely applied inmany fields, such as medicine, conductive materials and organic optical functionalmaterials. Owing to a special fragment consisting of the C=N group with a loneelectron pair, Schiff base can cooperate with many metal ions. The Schiff bases withthe structures of conjugated segments of big π bond usually have excellentfluorescence properties. In this paper, six novel conjugated Schiff bases are prepared.And their fluorescence properties and the ability to detect metal ions are studied.(1) Two novel conjugated Schiff bases were synthesized by condensationreactions between indole-3-carbaldehyde or5-methoxyindole-3-carbaldehyde and p-phenylenediamine respectively. The structures of the synthetic compounds werecharacterized by IR and NMR. The synthesis process were optimized, the productyield were greatly improved. Their fluorescence properties and the ability to detectmetal ions were studied.(2) Two novel conjugated Schiff bases were synthesized by condensationreactions between indole-3-carbaldehyde or5-methoxyindole-3-carbaldehyde and o-phenylenediamine respectively. The structures of the synthetic compounds werecharacterized by IR and NMR. The synthesis process were optimized, the productyield were greatly improved. Their fluorescence properties and the ability to detectmetal ions were studied.(3)4-carbazol-9-ylbenzaldehyde was synthesized using carbazole and4-fluo-robenzaldehyde. Then two novel conjugated Schiff bases were synthesized bycondensation reactions between4-carbazol-9-ylbenzaldehyde and p-phenylenediamine or o-phenylenediamine respectively. The structures of the syntheticcompounds were characterized by IR,1H NMR and elemental analysis. The synthesisprocess were optimized, the product yield were greatly improved. Their fluorescenceproperties and the ability to detect metal ions were studied.In this work, a series of conjugated Schiff bases with novel struvture based onindole or carbazole were synthesized. These compounds with excellent fluorescenceproperties exhibit good ability to detect metal ions.