| Abstrakt: |
By the reaction of N'-(4-formyl-2,3-dihydro-1H-benzo[b]xanthen-12-yl)-N,N-dimethylimidoformamide and N'-(6-formyl-7,8,9,10- tetrahydrocyclohepta[b]chromen-11-yl)-N,N-dimethylimidoformamide with malononitrile and cyanoacetic acid ethyl ester, the following two new dyes were synthesized by basic catalysis: N'-[4-(2,2-dicyanovinyl)-2,3-dihydro-1H-benzo[b]xanthen-12-yl]-N,N-dimethylimidoformamide and ethyl (2E)-2-cyano-3-(11-{[(1E)-(dimethylamino)methylene]amino}-7,8,9,10-tetrahydrocyclohepta-[b]chromen-6-yl)acrylate. Both dyes in solution have a purple color with high extinction coefficients, but due to the different size of the partially saturated cycle, the first one displays fluorescence, and the second one does not. The fluorescence quantum yields for N'-(4-formyl-2,3-dihydro-1H-benzo[b]xanthen-12-yl)-N,N-dimethylimidoformamide decrease with decreasing solvent polarity. For example, the highest emission quantum yield is observed in methanol (2.76%), while the smallest is observed in tetrahydrofuran (1.04%). It is due to the fact that methanol implies a lesser energy consumption during the redistribution of electron density in the excited state. N'-[4-(2,2-dicyanovinyl)-2,3-dihydro-1H-benzo[b]xanthen-12-yl]-N,N-dimethylimidoformamide dye can be used as a fluorophore, whereas ethyl (2E)-2-cyano-3-(11-{[(1E)-(dimethylamino)methylene]amino}-7,8,9,10-tetrahydrocyclohepta[b]chromen-6-yl)acrylate dye can be used as a light filter to create a variety of materials and devices. In addition, the synthesized compounds can be used as building-blocks in organic chemistry. [ABSTRACT FROM AUTHOR] |
