Likhtenstein Gertz I, Ishii Kazuyuki, Nakatsuji Shin'ichi
Department of Chemistry, Ben-Gurion University of Negev, Be'er-Sheva, Israel.
Photochem Photobiol. 2007 Jul-Aug;83(4):871-81. doi: 10.1111/j.1751-1097.2007.00141.x.
Over the last decades scientists have faced growing requirements in novel methods of fast and sensitive analysis of antioxidant status of biological systems, spin redox probing and spin trapping, investigation of molecular dynamics, and of convenient models for studies of photophysical and photochemical processes. In approaching this problem, methods based upon the use of dual chromophore-nitroxide (CN) compounds have been suggested and developed. A CN consists of two molecular sub-functionality (a chromophore and a stable nitroxide radical) tethered together by spacers. In the dual compound the nitroxide is a strong intramolecular quencher of the fluorescence from the chromophore fragment. Reduction to hydroxylamine, oxidation of the nitroxide fragment or addition of an active radical yield the fluorescence increase and the parallel decay of the fragment electron spin resonance (ESR) signal. At certain conditions the dual molecules undergo photomagnetic switching and form excited state multi-spin systems. These unique properties of CN were intensively exploited as the basis for several methodologies, which include molecular probing, modeling intramolecular photochemical and photophysical processes, and construction of new magnetic materials.
在过去几十年里，科学家们面临着对生物系统抗氧化状态进行快速、灵敏分析的新方法、自旋氧化还原探测和自旋捕获、分子动力学研究以及用于光物理和光化学过程研究的便捷模型等方面日益增长的需求。为了解决这个问题，基于使用双发色团 - 氮氧化物（CN）化合物的方法被提出并得到发展。一个CN由通过间隔基连接在一起的两个分子子功能（一个发色团和一个稳定的氮氧化物自由基）组成。在双化合物中，氮氧化物是发色团片段荧光的强分子内猝灭剂。还原为羟胺、氮氧化物片段的氧化或添加活性自由基会导致荧光增强以及片段电子自旋共振（ESR）信号的平行衰减。在特定条件下，双分子会发生光磁转换并形成激发态多自旋系统。CN的这些独特性质被广泛用作多种方法的基础，这些方法包括分子探测、模拟分子内光化学和光物理过程以及构建新型磁性材料。
