Radical cations of fulvenes: planar or twisted?
Radical cations of fulvenes: planar or twisted?
复制标题
富烯的自由基阳离子：平面还是扭曲？
DOI：
10.1021/ja00310a012
复制
发表时间：
1986
影响因子：
15
通讯作者：
H. D. Roth
中科院分区：
文献类型：
--
作者：
C. Abelt;H. D. Roth
几种富烯衍生物与光激发电子受体（四氯苯醌、蒽醌）的反应产生强的核自旋极化效应。这些结果提供了洞察自由基阳离子中间体的结构。对于所研究的所有系统，自旋密度仅限于环碳。外亚甲基位置上的给电子取代基影响阳离子自由基中正电荷的离域和环外键的强度。例如，（Z）-和（Z）-叔丁基-O-叔二甲基氨基]富烯自由基阳离子容易重排，而二叔丁基富烯自由基阳离子不显示相互转化。结果是兼容的平面或轻微扭曲的自由基阳离子，并排除垂直自由基阳离子的中间。
The reactions of several fulvene derivatives with photoexcitedelectron acceptors (chloranil, anthraquinone) give rise to strong nuclear spin polarization effects. These results offer insight into the structures of the radical cation intermediates. For all systems studied, the spin density is restricted to the ring carbons. Electron-donating substituents in the exomethylene position affect the delocalization of the positive charge and the strength of the exocyclic bond in the radical cations. For example, the (Z)-and (Zj^-terí-butyl-ó-tdimethylaminojfulvene radical cations rearrange readily, whereas the di-tert-butylfulvene z radical cations show no interconversion. The results are compatible with either planar or slightly twisted radical cations and preclude the intermediacy of perpendicular radical cations.