Department of Chemistry, University of California, Berkeley , Berkeley, California 94720, United States.
Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
J Am Chem Soc. 2017 Jul 19;139(28):9447-9450. doi: 10.1021/jacs.7b04602. Epub 2017 Jul 3.
By recording both the images and emission spectra of thousands of single fluorescent molecules stochastically generated from the ring-opening reaction of a spiropyran, we provide mechanistic insights into its multipath reaction pathways. Through statistics of the measured single-molecule spectra, we identify two spectrally distinct isomers, presumably TTC and TTT cis-trans isomers, for the open-ring merocyanine product, and discover a strong solvent polarity-dependence for the relative population of the two isomers. From single-molecule spectral time traces, we further examine isomerization between the two product merocyanine isomers, as well as their ring-closure reaction back to the spiropyran form.
通过记录数千个随机生成于螺噁嗪开环反应的单个荧光分子的图像和发射光谱，我们深入了解了其多路径反应途径。通过对所测单分子光谱的统计，我们确定了开环副品红产物的两种光谱上明显不同的异构体，推测为 TTC 和 TTT 顺反异构体，并发现两种异构体的相对比例对溶剂极性有很强的依赖性。从单分子光谱时间轨迹，我们进一步研究了两种产物副品红异构体之间的异构化，以及它们环合回到螺噁嗪形式的反应。
