The first electronically stabilized phenalenyl radical: Effect of substituents on solution chemistry and solid-state structure
The first electronically stabilized phenalenyl radical: Effect of substituents on solution chemistry and solid-state structure
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DOI：
10.1021/cg0603366
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发表时间：
2007-04-01
影响因子：
3.8
通讯作者：
Haddon, Robert C.
中科院分区：
文献类型：
--
作者：
Beer, Leanne;Mandal, Swadhin K.;Haddon, Robert C.
我们报告了氧和硫取代对苯酚基中性自由基二聚影响的研究；这些取代基有望在电子上稳定自由基，同时在空间上干扰二聚化。 1,3,4,9-四甲氧基苯那烯基 (7a) 和 1-乙氧基-3,4,9-三甲氧基苯那烯基 (7b) 自由基是通过阳离子盐的化学还原制备的，但通过 X 射线晶体学显示，从这些溶液中分离出的晶体由烷氧基取代的芘组成。 1,9-二噻吩基 (8) 的结晶产生了 pi-二聚体，这是基于单个苯吩基单元的自由基的第一个例子，该基团通过电子效应而不是通过空间庞大的取代基的存在而在固态下稳定以防止 σ 二聚化。
We report an investigation into the effect of oxygen and sulfur substitution on the dimerization of phenalenyl-based neutral radicals; these substituents are expected to electronically stabilize the free radical while sterically interfering with dimerization. The 1,3,4,9-tetramethoxyphenalenyl (7a) and 1-ethoxy-3,4,9-trimethoxyphenalenyl (7b) radicals are prepared by chemical reduction of the cation salts, but the crystals that are isolated from these solutions are shown to be composed of alkoxy-substituted peropyrenes by X-ray crystallography. Crystallization of 1,9-dithiophenalenyl (8) gives rise to a pi-dimer, and this is the first example of a radical based on a single phenalenyl unit that has been stabilized against sigma-dimerization in the solid state by electronic effects rather than by the presence of sterically bulky substituents.