Several cross-conjugate enone compounds with different electron withdrawing substituents have been synthesized. The spectroscopy and photophysical behavior of these compounds in different conditions were studied. Resu...Several cross-conjugate enone compounds with different electron withdrawing substituents have been synthesized. The spectroscopy and photophysical behavior of these compounds in different conditions were studied. Results show that TICT formation which depends strongly on the solvent polarity and electron withdrawing ability of substituents was observed for compounds with different electron withdrawing groups.For compound (Ⅳ) which possesses strong electron withdrawing ability, the TICT formation can be ob served in weak polar solvent, such as in toluene. But, for compounds (Ⅱ) and (Ⅲ), it can be observed in THF and ethyl ether, respectively. It can also be observed that the fluorescence quanum yields of these compounds are varied with the solvent polarity, and a maximum appears in this variation. Results obtaind have been discussed preliminary.展开更多
The fluorescence spectra in cyclohexane of a series of benzanilides(BAs) with different \%para\% substituents at the anilino moiety revealed that BAs emitted dual fluorescence, with one normal weak emission at ca . 33...The fluorescence spectra in cyclohexane of a series of benzanilides(BAs) with different \%para\% substituents at the anilino moiety revealed that BAs emitted dual fluorescence, with one normal weak emission at ca . 330 nm and an abnormally long wavelength emission ranging from 460 to 550 nm. The long wavelength emission was found strongly dependent of the electron donating capacity of the substituent at the anilino moiety and a stronger electron donating substituent led to a red shift in the emission. The energies of the long wavelength emission of the BAs were correlated to the oxidation potentials of the donors, E \-\{D/D +\}, and a nice linear correlation was found with a slope of +0 66, which clearly pointed to the charge transfer character of the emissive state for the long wavelength emission and the high decoupling extent of the charges in the CT state. This is the first report that shows the direct evidence for the CT nature. The results might be of significance in understanding the photophysics of peptide and protein and in designing novel fluorescent chemosensors.展开更多
文摘Several cross-conjugate enone compounds with different electron withdrawing substituents have been synthesized. The spectroscopy and photophysical behavior of these compounds in different conditions were studied. Results show that TICT formation which depends strongly on the solvent polarity and electron withdrawing ability of substituents was observed for compounds with different electron withdrawing groups.For compound (Ⅳ) which possesses strong electron withdrawing ability, the TICT formation can be ob served in weak polar solvent, such as in toluene. But, for compounds (Ⅱ) and (Ⅲ), it can be observed in THF and ethyl ether, respectively. It can also be observed that the fluorescence quanum yields of these compounds are varied with the solvent polarity, and a maximum appears in this variation. Results obtaind have been discussed preliminary.
文摘The fluorescence spectra in cyclohexane of a series of benzanilides(BAs) with different \%para\% substituents at the anilino moiety revealed that BAs emitted dual fluorescence, with one normal weak emission at ca . 330 nm and an abnormally long wavelength emission ranging from 460 to 550 nm. The long wavelength emission was found strongly dependent of the electron donating capacity of the substituent at the anilino moiety and a stronger electron donating substituent led to a red shift in the emission. The energies of the long wavelength emission of the BAs were correlated to the oxidation potentials of the donors, E \-\{D/D +\}, and a nice linear correlation was found with a slope of +0 66, which clearly pointed to the charge transfer character of the emissive state for the long wavelength emission and the high decoupling extent of the charges in the CT state. This is the first report that shows the direct evidence for the CT nature. The results might be of significance in understanding the photophysics of peptide and protein and in designing novel fluorescent chemosensors.
