A β-diketone-bridged chromophore-containing acrylic monomer, 1-(4-dimethylaminophenyl)-4-methyl-4-pentene-1,3-diketone(DMPDK) and its saturated model compound, 1-(4-dimethyl aminophenyl)-1,3-butanedione(DMBDK) were s...A β-diketone-bridged chromophore-containing acrylic monomer, 1-(4-dimethylaminophenyl)-4-methyl-4-pentene-1,3-diketone(DMPDK) and its saturated model compound, 1-(4-dimethyl aminophenyl)-1,3-butanedione(DMBDK) were synthesized and investigated by spectroscopy. It was found that the fluorescence intensity of DMPDK was much lower than that of DMBDK at the same concentration, which indicates that DMPDK, a β-diketone-bridged acrylic monomer having chromophore moiety, also showed fluorescence structural self-quenching effect(SSQE). Photo-induced tautomerization of DMBDK in acetonitrile was studied by means of UV and fluorescence spectroscopy. The results imply that the fluorescence method is capable of monitoring tautomerization of some fluorescent β-diketones.展开更多
Azobenzene-modified pullulan with different substitution degrees were prepared by changing feed molar ratio of 4-phenylazophenyloxybutyrate acid to pullulan. The structure of the modified pullulan were characterized b...Azobenzene-modified pullulan with different substitution degrees were prepared by changing feed molar ratio of 4-phenylazophenyloxybutyrate acid to pullulan. The structure of the modified pullulan were characterized by 1 H NMR and FTIR spectroscopies. The substitution degrees were determined by elemental analysis and UV-Vis spectra. Photochromism property in solution was investigated by UV-Vis spectroscopy, isomerization behavior of azobenzene moeties of polymer under irradiation at 350 nm is obvious. After 4 min irradiation, trans isomer of sample 3 change into cis isomer completely. Furthermore, unlike pullulan, which is soluble only in H2O or DMSO, the solubility of these products in common organic solvent increased greatly.展开更多
文摘A β-diketone-bridged chromophore-containing acrylic monomer, 1-(4-dimethylaminophenyl)-4-methyl-4-pentene-1,3-diketone(DMPDK) and its saturated model compound, 1-(4-dimethyl aminophenyl)-1,3-butanedione(DMBDK) were synthesized and investigated by spectroscopy. It was found that the fluorescence intensity of DMPDK was much lower than that of DMBDK at the same concentration, which indicates that DMPDK, a β-diketone-bridged acrylic monomer having chromophore moiety, also showed fluorescence structural self-quenching effect(SSQE). Photo-induced tautomerization of DMBDK in acetonitrile was studied by means of UV and fluorescence spectroscopy. The results imply that the fluorescence method is capable of monitoring tautomerization of some fluorescent β-diketones.
文摘Azobenzene-modified pullulan with different substitution degrees were prepared by changing feed molar ratio of 4-phenylazophenyloxybutyrate acid to pullulan. The structure of the modified pullulan were characterized by 1 H NMR and FTIR spectroscopies. The substitution degrees were determined by elemental analysis and UV-Vis spectra. Photochromism property in solution was investigated by UV-Vis spectroscopy, isomerization behavior of azobenzene moeties of polymer under irradiation at 350 nm is obvious. After 4 min irradiation, trans isomer of sample 3 change into cis isomer completely. Furthermore, unlike pullulan, which is soluble only in H2O or DMSO, the solubility of these products in common organic solvent increased greatly.
