Study On Synthesis And Luminescent Properties In Imidazole Derivatives

Imidazole ring with a non-center symmetrical structure isÏ€electron deficient, which may link to strong electron-withdrawing groups and have excellent properties of electronic transmission. Imidazole-based compuonds are excellent organic non-linear optical materials. Arylimidazoles have prodigious potentialities in the field of electroluminescence and Photoluminescence.The paper is composed of three sections as follow:1. Benzil was synthesized from benzaldehyde by benzoin condensation and oxidation. 2,4,5-diphenylimidazole were prepared by Debus reaction. The reaction conditions such as the type of ammonium and solvent, the amount of ammonium acetate and benzaldehyde dosage as well as the reaction time were discussed. 2-(4'-hydroxyphen -yl)-4,5-triphenylimidazole, 2-(4'-methoxyphenyl)-4,5–triphenylimi -dazole, 2-(4'-chlorophenyl)-4,5-triphenylimidazole, 2-(4'-nitropheny -l)-4,5-triphenylimidazole, 2-(2'-hydroxyyl)-4,5-triphenylimidazole were synthesized under the optimized conditions. The structures of all these compounds were characterized by FI-IR and H1 NMR.2. UV spectrum and fluorescence spectrum were assayed, besides, quantum yield was calculated. The relationship of molecular structure and fluorescence properties was thoroughly discussed. Then, we summarized the external and internal factors that influencing the fluorescence properties discussed the different substituting group thoroughly to the fluorescence spectrum influence, and finally indicated that -OH had the good spectrum performance for the electronic groups and bases: a stokes' shift with 110 nm, the fluorescence quantum yield of 72.05 %. It had very good application potential in the luminescent material domain.3. The recognition performance of different kinds of metallic ion such as (Zn²⁺,K⁺,Na⁺,Fe³⁺,Al³⁺,Ca²⁺,Cu²⁺,Mg²⁺) and Mg²⁺ to 2-(2-hydroxyphenyl)-4,5-diphenylimidazole have been tested using the fluorescence spectrum. The results demonstrated that only the cupric ion had good fluorescence quenching phenomenon to it. Then the fluorescence spectrum of 2-(2-hydroxyphenyl)-4,5-diphen -ylimidazole along with the change of Cu²⁺ sdensity was assayed, which showed linear variation. It showed that 2-(2-hydroxyphenyl)-4, 5-diphenylimidazole was good fluorescence sensor selectively testing Cu²⁺.