Continuous wave electron paramagnetic resonance of nitroxide biradicals in fluid solution
Continuous wave electron paramagnetic resonance of nitroxide biradicals in fluid solution
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DOI：
10.1002/cmr.a.21426
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发表时间：
2018-03-01
影响因子：
0.6
通讯作者：
Eaton, Gareth R.
中科院分区：
文献类型：
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作者：
Eaton, Sandra S.;Woodcock, Lukas B.;Eaton, Gareth R.
氮氧双自由基已制备电子-电子自旋-自旋交换相互作用，J，范围从弱到很强。这些双自由基在流体溶液中的EPR谱取决于J的氮超精细耦合，A（N）的比率，和具有不同J值的构象之间的相互转化率。对于相对刚性的双自由基EPR谱可以模拟为AB分裂模式的叠加所产生的氮核自旋态的不同组合。对于更灵活的双自由基光谱可以模拟与刘维表示的动态相互转换的构象与不同的J值的EPR时标。光谱分析，影响J的因素，以及化学和生物物理问题的应用实例进行了讨论。
Nitroxide biradicals have been prepared with electron-electron spin-spin exchange interaction, J, ranging from weak to very strong. EPR spectra of these biradicals in fluid solution depend on the ratio of J to the nitrogen hyperfine coupling, A(N), and the rates of interconversion between conformations with different values of J. For relatively rigid biradicals EPR spectra can be simulated as the superposition of AB splitting patterns arising from different combinations of nitrogen nuclear spin states. For more flexible biradicals spectra can be simulated with a Liouville representation of the dynamics that interconvert conformations with different values of J on the EPR timescale. Analysis of spectra, factors that impact J, and examples of applications to chemical and biophysical problems are discussed.