C20H4(C4F8)3: A Fluorine-Containing Annulated Corannulene that Is a Better Electron Acceptor Than C60
C20H4(C4F8)3: A Fluorine-Containing Annulated Corannulene that Is a Better Electron Acceptor Than C60
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DOI：
10.1002/anie.201300796
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发表时间：
2013-07-15
影响因子：
16.6
通讯作者：
Boltalina, Olga V.
中科院分区：
文献类型：
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作者：
Kuvychko, Igor V.;Dubceac, Cristina;Boltalina, Olga V.
人们对用于能量转换和储存的小聚芳族分子、有机晶体管和有机发光二极管（OLED）以及现代技术的其他新兴领域的设计和应用越来越感兴趣。[1]特别地，官能化的多环芳烃（PAH）在有机薄膜晶体管中已经表现出优异的电迁移率，在某些情况下甚至在环境条件下也是如此。[2]已经提出，这种有机材料的空气稳定性与它们的电子性质相关，更具体地说，与高电子亲和力相关。[3]直到最近，测地多环芳烃，如corannulene [4]和sumanene，[5]以及它们的许多衍生物，还没有被认真考虑用于光电应用，因为1）它们通常具有非常低的电子亲和力（例如EA（C20 H10）= 0.5（1）eV），[6]和2）费力的多步合成，中低产率使它们实际上无法用于此类研究。[7]尽管苏曼烯的低可用性保持不变，但最近在大规模合成corannulene方面取得了重大进展。[8]此外，我们最近的研究表明，与吸电子基团（EWG）的功能化corannulene的结果在其电子受体性质的急剧增强。[9]特别地，观察到三氟甲基化衍生物C20 H5（CF 3）5的还原电位相对于母体C20 H10的950 mV正移。我们还预测，其他EWG，包括卤素原子或氰化物基团，可以用来提高corannulene的电子亲和势。EWG的数量和相应EWG取代的corannulene的电子亲和力（还原电位）之间的近似线性相关性通过我们的DFT计算证明，并且最近，对于C20 H10-x（CF 3）x（x= 2，3）得到证实，[10]允许设计具有所需电子性质的分子。在这里，我们报告的第一个合成，结构和电子性质1与35当量的1，4-C_4F_8I_2在300 ℃下反应得到浅黄色粗产物，根据负离子大气压化学电离（NIAPCI）质谱，由三种主要类型的分子种类组成，通式为C20 H4（C4 F8）3，C20 H4（C4 F8）4，和C20 H4（C4 F8）4（C4 F8 I）（参见支持信息中的图S1 A）。随后通过1H和19 F NMR光谱法对粗物质进行分析，结果显示原料1完全消耗，并且两种主要产物是Cs-C20 H4（C4 F8）3的异构体（2和3，参见方案1）。
There has been increased interest in the design and applications of small polyaromatic molecules for energy conversion and storage, organic transistors and organic light-emitting diodes (OLEDs), and other emerging areas of modern technology.[1] In particular, functionalized polycyclic aromatic hydrocarbons (PAHs) have demonstrated excellent electrical mobilities in organic thin-film transistors, in some cases even under ambient conditions.[2] It has been suggested that the air stability of such organic materials is correlated with their electronic properties and, more specifically, with a high electron affinity.[3] Until recently, geodesic PAHs, such as corannulene [4] and sumanene,[5] as well as their numerous derivatives, have not been seriously considered for optoelectronic applications because 1) they typically possess very low electron affinities (eg EA (C20H10)= 0.5 (1) eV),[6] and 2) laborious multistep syntheses with moderate-to-low yields made them practically unavailable for such studies.[7] Although the low availability of sumanene remains unchanged, significant progress has been made recently in the large-scale synthesis of corannulene.[8] Furthermore, our recent studies demonstrated that functionalization of corannulene with electron-withdrawing groups (EWGs) results in a drastic enhancement of its electron-acceptor properties.[9] In particular, a 950 mV positive shift in the reduction potential for the trifluoromethylated derivative C20H5 (CF3) 5 relative to the parent C20H10 was observed. We also predicted that other EWGs, including halogen atoms or a cyanide group, could be used to enhance the electron affinity of corannulene. The nearly linear correlation between the number of EWGs and the electron affinity (reduction potential) of the corresponding EWG-substituted corannulene demonstrated by our DFT calculations, and, more recently, confirmed for C20H10-x (CF3) x (x= 2, 3),[10] allows for the design of molecules with the desired electronic properties. Here, we report the first synthesis, structure, and electronic properties (in solution and in the gas phase) of a derivative of corannulene, which has a higher electron affinity (EA) than the well-studied fullerene electron-acceptor C60.The reaction of 1 with 35equivalents of 1, 4-C4F8I2 at 3008C led to a pale-yellow crude product, which, according to negative-ion atmospheric pressure chemical ionization (NIAPCI) mass spectrometry, consisted of three major types of molecular species with the general formulas C20H4 (C4F8) 3, C20H4 (C4F8) 4, and C20H4 (C4F8) 4 (C4F8I)(see Figure S1 A in the Supporting Information). Subsequent analysis of the crude material by 1H and 19F NMR spectroscopy showed that the starting material 1 was completely consumed, and that the two major products were isomers of Cs-C20H4 (C4F8) 3 (2 and 3, see Scheme 1).