Fluorophenoxycarbene inside a Hemicarcerand: A Bottled Singlet Carbene


  • This research was supported by the NSF (Grants CHE-0431749 to R.W. and CHE-0345240 to R.A.M.) and Rutgers University. We thank Dr. Seho Kim for assistance with NMR spectroscopic experiments and Prof. Karsten Krogh-Jespersen for helpful suggestions.


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Long live the carbene: Longevity is granted to fluorophenoxycarbene when it is generated photochemically from fluorophenoxydiazirine (see picture) inside a hemicarcerand. This fleeting, and otherwise nonisolable, singlet carbene is the first electron-deficient species that has been stabilized by trapping. NOE experiments suggest that the carbene adopts the intrinsically less stable cis conformation in the confined inner phase.