کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5391432 | 1505101 | 2008 | 4 صفحه PDF | دانلود رایگان |

We report the effect of a N-methylpyridinium substituent on the photoacidity enhancement of a phenol derivative. The steady-state and time-resolved fluorescence of this new phenolic 'super' photoacid (HPPy) are measured in different solvents in comparison with its methoxy analogue (MPPy). Solvatochromic shifts and nonradiative rate constants ascribable to excited state proton transfer (ESPT) are correlated with the empirical Kamlet-Taft parameters (Ï*, α, and β). Whereas, spectral shift of MPPy is mainly correlated to Ï* parameter, HPPy is also strongly influenced by β. At 77 K, ESPT is hampered and leads to the switch 'on' emission of conjugated base.
Excited state proton transfer process in various pure solvents is investigated in a novel phenol-pyridinium biaryl chromophore
Journal: Chemical Physics Letters - Volume 455, Issues 4â6, 10 April 2008, Pages 238-241