Using Stable Radicals To Protect Pentacene Derivatives from Photodegradation
Using Stable Radicals To Protect Pentacene Derivatives from Photodegradation
复制标题
使用稳定的自由基保护并五苯衍生物免遭光降解
DOI：
10.1002/anie.201300595
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Y. Teki
中科院分区：
文献类型：
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作者：
Y. Kawanaka;A. Shimizu;T. Shinada;R. Tanaka;Y. Teki
Organic transistors and organic devices have a variety of applications in molecular electronics [1–3] and in the up-andcoming area of organic molecular spintronics.[4] The use of inexpensive and facile ink-jet methods [5] is possible for the fabrication of organic semiconductors. Pentacene and its derivatives [6, 7] have attracted increasing interest as promising electronic materials owing to their high hole mobility.[8] Pentacene is the most promising candidate for organic fieldeffect transistor (OFET) applications.[3, 8] However, its chemical instability in the presence of light and air [9] prevents practical applications. Efforts have been made to improve the stability by the addition of substituents.[6, 7] The most notable example is 6, 13-bis (triisopropylsilylethynyl) pentacene,[7, 10] in which the 6-and 13-positions of pentacene are protected by triisopropylsilylethynyl groups. For this pentacene derivative, extremely high hole mobility of 1.8 cm2 VÀ1 sÀ1 was reported for the thin film.[8] However, the addition of substituents to photoactive carbon sites prevents further functional modifications because both the 6-and 13-positions are blocked by the substituents and also the characteristic nature of the pentacene moiety is changed. Herein, we report a new method that utilizes a stable radical to protect pentacene derivatives from photodegradation. During the course of our systematic studies of pconjugated spin systems with high-spin photo-excited states for functional materials,[11] we have discovered that a combination of two unstable species (photoreactive pentacene and a radical) leads to remarkable protection from photodegradation and an enhancement in solubility in common organic solvents. These effects are advantageous for practical applications of acene derivatives in molecular electronic devices. Radicals are well-known energy scavengers of the photoexcited state. We have utilized this characteristic of radicals to scavenge the energy of the photoexcited state of pentacene. Two novel radical pentacene hybrids, Pen–Ph–OV (1a) and
