Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
Org Lett. 2011 Jul 1;13(13):3316-9. doi: 10.1021/ol201004u. Epub 2011 Jun 7.
The electronic ground states of the recently synthesized stable nonacene derivatives (J. Am. Chem. Soc. 2010, 132, 1261) are open-shell singlets with a polyradical nature instead of closed-shell singlets as originally assumed, according to the unrestricted broken spin-symmetry density functional theory (UBS-DFT) computations (at B3LYP/6-31G*). It is the bulky protecting groups, not the transfer from the open-shell singlet to closed-shell singlet ground state, that stabilizes these longest characterized acenes. Similar analyses also confirmed the open-shell singlet character of the hexacene and teranthene derivatives.
根据无限制的断自旋对称密度泛函理论（UBS-DFT）计算（在 B3LYP/6-31G*水平上），最近合成的稳定的非并苯衍生物（美国化学会志，2010 年，第 132 卷，第 1261 页）的电子基态是具有多自由基性质的开壳 singlet，而不是最初假设的闭壳 singlet。这些最长特征化的并苯稳定的是体积庞大的保护基团，而不是从开壳 singlet 到闭壳 singlet 基态的转变。类似的分析也证实了六并苯和三角并苯衍生物的开壳 singlet 性质。
