Getoff N, Solar S
Science. 1978 Aug 18;201(4356):616-8. doi: 10.1126/science.675244.
Riboflavin and 12 of its derivatives have been shown to form solvated electrons under ultraviolet irradiation (253.7 nanometers) in various water-methanol solvent mixtures. The highest quantum yield of solvated electrons (about 0.03) was obtained for flavins containing tyrosine on a side chain in the isoalloxazine N-3 or N-10 position. The splitting of hydrogen atoms from excited flavin molecules was also observed. From the results presented here, it can be determined that the semiquinone transients are formed not only by way of the flavin triplet, as usually suggested, but also by the attack of the electrons and hydrogen atoms on flavin molecules in the ground state. This is important, because the flavin radicals remaining after the electron-ejection or hydrogen-splitting processes must also be considered in the subsequent reaction mechanisms. The electron-ejection process from electronically excited flavins has important implications in the photobiology of these compounds.
已证明核黄素及其12种衍生物在各种水 - 甲醇溶剂混合物中，于紫外线照射（253.7纳米）下会形成溶剂化电子。对于在异咯嗪N - 3或N - 10位侧链含有酪氨酸的黄素，溶剂化电子的量子产率最高（约0.03）。还观察到激发态黄素分子中的氢原子分裂。根据此处给出的结果，可以确定半醌瞬态不仅如通常所认为的那样通过黄素三重态形成，还通过电子和氢原子对基态黄素分子的攻击形成。这很重要，因为在后续反应机制中也必须考虑电子射出或氢分裂过程后剩余的黄素自由基。从电子激发的黄素中射出电子的过程对这些化合物的光生物学具有重要意义。
