Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel.
J Phys Chem A. 2010 Aug 12;114(31):8075-82. doi: 10.1021/jp103264y.
Steady-state absorption and emission as well as time-resolved emission spectroscopies were employed to study the photophysics and photochemistry of D-luciferin, the firefly active bioluminescent compound. In aqueous solution the electronically excited-state protonated D-luciferin compound undergoes an efficient process of proton transfer to the solvent, with a rate constant k(PT) = 3.0 x 10(10) s(-1). We found a kinetic isotope effect of about 2.5 for this process. The deprotonated form of D-luciferin in the excited state recombines irreversibly with the geminate proton. Hence, the fluorescence decay of the deprotonated form is nonexponential, and the fluorescence quantum yield is low.
稳态吸收和发射以及时间分辨发射光谱学被用来研究萤火虫生物发光化合物 D-荧光素的光物理和光化学。在水溶液中，电子激发态的质子化 D-荧光素化合物经历一个向溶剂的质子转移的有效过程，速率常数 k(PT) = 3.0 x 10(10) s(-1)。我们发现这个过程的动力学同位素效应约为 2.5。在激发态下，D-荧光素的去质子形式不可逆地与孪生质子重新结合。因此，去质子形式的荧光衰减是非指数的，荧光量子产率很低。
