Synthesis and Spectral Properties of 4-（2,5-Dimethoxyphenyl- methelene）-2-phenyl-5-oxazolone （DMPO）  

作　　者：EI-Daly, Samy A Asiri, Abdullah M Alamry, Khalid A Hussein, Mahmoud A 

机构地区：[1]Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia [2]The Center of Excellence for Advanced Materials, King Abdulaziz University, Jeddah 21589, P.O. Box 80203, Saudi Arabia [3]Department of Chemistry, Faculty of Science, Tanta University, 31527 Tanta, Egypt [4]Chemistry Department, Faculty of Science, Assiut University, Assiut 71516, Egypt

出　　处：《Chinese Journal of Chemistry》2012年第3期563-569,共7页中国化学（英文版）

摘　　要：An interesting flourophore, 4-（2,5-dimethoxyphenylmethelene）-2-phenyl-5-oxazolone （DMPO） was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5-dimethoxybenzaldehyde in acetic anhydride in the presence of anhydrous sodium acetate. The absorption and fluorescence characteristics of 4-（2,5-dimethoxy-phenyl- methelene）-2-phenyl-5-oxazolone （DMPO） were investigated in different solvents. DMPO dye exhibits red shift in both absorption and emission spectra as solvent polarity increases, indicating change in the dipole moment of mole- cules upon excitation due to an intramolecular charge transfer interaction. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. A crystalline solid of DMPO gave strong excimer like emission at 630 nm due to the excitation of molecular aggregates. This is expected from the idealized crystal structure of the dye that belongs to the B-type class of Steven＇s Classifica- tion. DMPO displayed fluorescence quenching by triethylamine via nonemissive exciplex formation.An interesting flourophore, 4-（2,5-dimethoxyphenylmethelene）-2-phenyl-5-oxazolone （DMPO） was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5-dimethoxybenzaldehyde in acetic anhydride in the presence of anhydrous sodium acetate. The absorption and fluorescence characteristics of 4-（2,5-dimethoxy-phenyl- methelene）-2-phenyl-5-oxazolone （DMPO） were investigated in different solvents. DMPO dye exhibits red shift in both absorption and emission spectra as solvent polarity increases, indicating change in the dipole moment of mole- cules upon excitation due to an intramolecular charge transfer interaction. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. A crystalline solid of DMPO gave strong excimer like emission at 630 nm due to the excitation of molecular aggregates. This is expected from the idealized crystal structure of the dye that belongs to the B-type class of Steven＇s Classifica- tion. DMPO displayed fluorescence quenching by triethylamine via nonemissive exciplex formation.

关 键 词：4-（2 5-dimethoxy-phenylmethelene）-2-phenyl-5-oxazolone （DMPO） effect of medium fluorescencequantum yield solid state emission 

分 类 号：O621.146[理学—有机化学] TQ171.112[理学—化学]