Bagryanskaya Elena, Fedin Matvey, Forbes Malcolm D E
International Tomography Center, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia.
J Phys Chem A. 2005 Jun 16;109(23):5064-9. doi: 10.1021/jp050499p.
We report the first experimental study of chemically induced electron spin polarization (CIDEP) processes in low magnetic fields for spin-correlated radical pairs (SCRPs) in micellar environments. Photoexcitation of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TMBDPO) leads to the radical pair comprised of acyl radical 1 and phosphonyl radical 2. The spin polarization, which is very strong in free solution even at zero field, was detected using L-band time-resolved electron paramagnetic resonance (TREPR) spectroscopy with specially modified resonators. The mechanism of formation and decay of low field CIDEP in SCRPs is presented and discussed. The prominent difference between low and high field spectra in micelles is the absence of anti-phase structure for radical 2 with HFI a > B0. This feature is consistent with the proposed polarization mechanism and theoretical predictions.
我们报道了在胶束环境中，针对自旋相关自由基对（SCRPs）在低磁场下化学诱导电子自旋极化（CIDEP）过程的首次实验研究。（2,4,6 - 三甲基苯甲酰基）二苯基氧化膦（TMBDPO）的光激发产生了由酰基自由基1和膦酰基自由基2组成的自由基对。利用经过特殊改进的谐振器的L波段时间分辨电子顺磁共振（TREPR）光谱检测到了自旋极化，即使在零场时，其在自由溶液中也非常强。本文介绍并讨论了SCRPs中低场CIDEP的形成和衰减机制。胶束中低场和高场光谱的显著差异在于，对于超精细相互作用（HFI）a > B0的自由基2，不存在反相结构。这一特征与所提出的极化机制和理论预测一致。
