Bis-Spiro-Oxetane and Bis-Spiro-Tetrahydrofuran Pyrroline Nitroxide Radicals: Synthesis and Electron Spin Relaxation Studies
Bis-Spiro-Oxetane and Bis-Spiro-Tetrahydrofuran Pyrroline Nitroxide Radicals: Synthesis and Electron Spin Relaxation Studies
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双螺环氧杂环丁烷和双螺四氢呋喃吡咯啉氮氧化物自由基：合成和电子自旋弛豫研究
DOI：
10.1021/acs.joc.1c01670
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Rajca, Andrzej
中科院分区：
文献类型：
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作者：
Huang, Shengdian;Pink, Maren;Ngendahimana, Thacien;Rajca, Suchada;Eaton, Gareth R.;Eaton, Sandra S.;Rajca, Andrzej
双螺环氧杂环丁烷和双螺环四氢呋喃吡咯啉氮氧自由基的合成依赖于Mitsunobu反应介导的N-Boc保护的吡咯啉四醇的双环化。氮氧自由基的结构由X射线晶体学支持。在室温下，在海藻糖/蔗糖基质中，双螺环氧杂环丁烷氮氧自由基具有电子自旋相干时间Tm = 0.7 μs。观察到的Tmis增强最有可能与氧杂环丁烷部分与海藻糖/蔗糖基质的强氢键有关。
Synthesis of bis-spiro-oxetane and bis-spiro-tetrahydrofuran pyrroline nitroxide radicals relies on the Mitsunobu reaction-mediated double cyclizations ofN-Boc protected pyrroline tetraols. Structures of the nitroxide radicals are supported by X-ray crystallography. In a trehalose/sucrose matrix at room temperature, the bis-spiro-oxetane nitroxide radical possesses electron spin coherence time,Tm≈ 0.7 μs. The observed enhancedTmis most likely associated with strong hydrogen bonding of oxetane moieties to the trehalose/sucrose matrix.