Molecular Engineering of Organic Semiconductors: Dibenzo[a,m]rubicene, Tetrabenzo[7]circulene and N-Hetero rubrene

• Other Authors: Gu, Xiao (author.)
• Format: Others
• Language: English; Chinese
• Published: 2016
• Online Access: http://repository.lib.cuhk.edu.hk/en/item/cuhk-1292188

此論文以含五元環和七元環的非平面多環芳香化合物和氮雜並苯為關注點，討論了有機半導體材料的分子工程，包含分子設計、分子合成以及對它們有機半導體性質的研究。 === 第一章介紹了有機半導體材料分子工程的兩大方向，即使平面的多環芳香化合物變為非平面及在並苯的骨架中引入氮雜原子。第一部分以螺烯和圈烯為重點介紹了它們的合成和分子結構，它們分別因空間原子擁擠效應和包含非六元環而偏離平面結構。第二部分以氮雜的並四苯及以上結構為重點，介紹了它們的合成、分子結構及其在有機薄膜晶體管中的應用。 === 第二章介紹了二苯並[a,m]玉紅省及其四個衍生物的合成。我們發現二苯並[a,m]玉紅省在單晶中的構象和分子堆積取決於其取代基的類型和大小。其中（三甲基硅基）乙炔基和（叔丁基二甲基硅基）乙炔基取代的二苯並[a,m]玉紅省在溶液法製備的有機薄膜晶體管中的空穴遷移率達到了1.0 cm2 V-1 s-1，這個結果優於那些已報導的含五元環的多環芳香化合物的空穴遷移率。 === 第三章介紹了具有對稱及不對稱結構的馬鞍型苯並及噻吩並[7]圈烯的合成。X射線晶體學結果表明四苯並[7]圈烯擁有比[7]圈烯更彎曲的骨架結構。四苯並[7]圈烯的HOMO能級表明其適合作為p型半導體，但是單晶中較弱的π-π相互作用導致其在有机薄膜晶体管中的空穴迁移率仅為6.2 × 10–4 cm2 V-1 s-1。 === 第四章介紹了氮雜6,13-二苯基並五苯和氮雜紅熒烯的合成和表徵。比較氮雜6,13-二苯基並五苯與6,13-二苯基並五苯的單晶結構，我們發現它們擁有相同的構型和分子排列，其中氮雜6,13-二苯基並五苯在有機薄膜電晶體中的空穴遷移率達到了0.037 cm2 V-1 s-1。相反，氮雜紅熒烯與紅熒烯的構型和分子排列極不相同，氮雜紅熒烯具有彎曲的骨架結構，其在單晶中只有極弱的π-π相互作用，並不適於用作有機半導體材料。 === Detailed in this thesis are molecular engineering of organic semiconductors with focus on pentagon/heptagon embedded non-planar polycyclic aromatic hydrocarbons (PAHs) and N-hetero acenes including design, synthesis and investigations on their organic semiconductor properties. === Chapter 1 introduces two directions for the molecular engineering of organic semiconductors, which are making otherwise planar PAHs to be non-planar and introducing N atoms to the backbone of acenes. The first part is focus on helicenes and circulenes which are forced out of planar by steric strain from atom crowding and by embedding non-hexagonal rings to planar PAHs, including syntheses and molecular structures. The second part is focus on larger N-hetero acenes with four or more fused six-membered rings involving syntheses, molecular structures and applications in organic thin film transistors (OTFTs). === Chapter 2 presents an efficient synthesis to dibenzo[a,m]rubicene and four of its derivatives and demonstrates that the conformation and molecular packing of dibenzo[a,m]rubicenes in the solid state are dependent on the substituting groups. With a non-planar conjugated backbone, trimethylsilyl ethynylated and dimethyl t-butyl ethynylated derivatives function as p-type organic semiconductors in solution processed OTFTs exhibiting field effect mobility of up to 1.0 cm2 V-1 s-1, which is higher than those of the reported semiconductors based on cyclopenta-fused PAHs. === Chapter 3 presents a convenient synthesis of saddle-shaped benzene- and thiophene-annulated [7]circulenes with either symmetric or asymmetric structures. X-ray crystallography shows that tetrabenzo[7]circulene is more curved than [7]circulene. With a suitable HOMO energy level but poor p-p interactions in the solid state, tetrabenzo[7]circulene functions as a p-type semiconductor with field effect mobility of up to 6.2 × 10–4 cm2 V–1 s–1 in OTFTs. === Chapter 4 presents the synthesis and characterization of N-hetero 6,13-diphenylpentacene (DPP) and N-hetero rubrene. N-hetero DPP exhibits the same conformation and molecular packing as its hydrocarbon analogue, DPP, and performs as a p-type semiconductor in OTFTs with hole mobility of up to 0.037 cm2 V–1 s–1. N-hetero rubrene differs from its hydrocarbon analogue, rubrene, by having a bowed backbone. The poor p-p interactions of N-hetero rubrene suggests an unfavorable molecular packing for organic semiconductors. === Gu, Xiao. === Thesis Ph.D. Chinese University of Hong Kong 2016. === Includes bibliographical references (leaves ). === Abstracts also in Chinese. === Title from PDF title page (viewed on …). === Detailed summary in vernacular field only. === Detailed summary in vernacular field only. === Detailed summary in vernacular field only. === Detailed summary in vernacular field only. === Detailed summary in vernacular field only.