Curve-Structured Phenalenyl Chemistry: Synthesis, Electronic Structure, and Bowl-Inversion Barrier of a Phenalenyl-Fused Corannulene Anion
Curve-Structured Phenalenyl Chemistry: Synthesis, Electronic Structure, and Bowl-Inversion Barrier of a Phenalenyl-Fused Corannulene Anion
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DOI：
10.1021/ja806708j
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发表时间：
2008-11-12
影响因子：
15
通讯作者：
Nakasuji, Kazuhiro
中科院分区：
文献类型：
--
作者：
Nishida, Shinsuke;Morita, Yasushi;Nakasuji, Kazuhiro
我们首次展示了曲线结构的非那烯基化学的特征。通过在corannulene的近位上连接一个六元环，设计了一种苯并萘基稠合corannulene阴离子，并在脱气溶液中以稳定的形式生成。H-1和C-13 NMR谱显示了高度对称的结构和高场位移的质子和碳在化学结构中的交叉位置，表明在这些位置发生大的负电荷密度。这些结果与HOMO图像和静电势面吻合得很好，表明在曲面Pi-体系中保留了非那烯基阴离子型的电子结构。计算的阴离子的碗反转势垒（11.3 kcal/mol）大于corannulene的碗反转势垒（9.2 kcal/mol），这是由于corannulene骨架的围环作用。计算的中性自由基（12.6千卡/摩尔），自由基二价阴离子（8.1千卡/摩尔），和三价阴离子（5.4千卡/摩尔）的phenalenyl-fused corannulene的势垒表现出逐步平坦的曲率与负电荷的增加。因此，我们揭示了阴离子的碗反转势垒是由周围的annealing和负电荷效应的抵消。
We have demonstrated the features of curve-structured phenalenyl chemistry, for the first time. A phenalenyl-fused corannulene anion has been designed by the annelation of a six-memberd ring across peri-positions of corannulene and generated as a stable species in a degassed solution. The H-1 and C-13 NMR spectra have shown the highly symmetrical structure and high-field shifts of protons and carbons at the asterisked positions in the chemical structure, indicating the occurrence of large negative charge densities at these positions. These results well agree with the HOMO picture and the electrostatic potential surface, demonstrating the phenalenyl anion-type electronic structure is retained in the curved-surface Pi-system. The calculated bowl-inversion barrier of the anion (11.3 kcal/mol) is larger than that of corannulene (9.2 kcal/mol) because of peri-annelation of the corannulene skeleton. The calculations of the barriers of the neutral radical (12.6 kcal/mol), radical dianion (8.1 kcal/mol), and trianion (5.4 kcal/mol) of the phenalenyl-fused corannulene have exhibited a stepwise flattening of the curvature with increase in negative charge. Therefore, we have revealed that the bowl-inversion barrier of the anion is governed by the setoff of the peri-annelation and negative charge effects.