低温下 5-叠氮基-3-苯基异恶唑的光解：亚硝烯的生成和直接检测。
Photolysis of 5-Azido-3-Phenylisoxazole at Cryogenic Temperature: Formation and Direct Detection of a Nitrosoalkene.
机构信息
Department of Chemistry, University of Cincinnati, PO Box 210172, Cincinnati, OH 45221-0172, USA.
Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, CA 94117, USA.
出版信息
Molecules. 2020 Jan 27;25(3):543. doi: 10.3390/molecules25030543.
To enhance the versatility of organic azides in organic synthesis, a better understanding of their photochemistry is required. Herein, the photoreactivity of azidoisoxazole was characterized in cryogenic matrices with IR and UV-Vis absorption spectroscopy. The irradiation (λ = 254 nm) of azidoisoxazole in an argon matrix at 13 K and in glassy 2-methyltetrahydrofuran (mTHF) at 77 K yielded nitrosoalkene . Density functional theory (DFT) and complete active space self-consistent field (CASSCF) calculations were used to aid the characterization of nitrosoalkene and to support the proposed mechanism for its formation. It is likely that nitrosoalkene is formed from the singlet excited state of azidoisoxazole via a concerted mechanism or from cleavage of an intermediate singlet nitrene that does not undergo efficient intersystem crossing to its triplet configuration.
为了提高有机叠氮化物在有机合成中的多功能性，需要更好地了解其光化学性质。在此，通过低温基质中的红外和紫外可见吸收光谱对叠氮异恶唑的光反应性进行了表征。在 13 K 的氩基质中和在 77 K 的玻璃状 2-甲基四氢呋喃（mTHF）中用 254nm 的光（λ = 254nm）照射叠氮异恶唑，生成亚硝酰烯 。使用密度泛函理论（DFT）和完全活性空间自洽场（CASSCF）计算来辅助亚硝酰烯的表征，并支持其形成的提议机制。亚硝酰烯 可能是通过协同机制从叠氮异恶唑的单重激发态形成的，或者是从不经历有效的系间窜跃到三重态构型的中间单重氮烯的断裂形成的。
Zotero 插件