ピラジンを含むアセンのタイプの分子リボンで,直線的に並べられた溶融したアロマティックリングが最大16個まであります
Baoxiang Gao1, Ming Wang, Yanxiang Cheng
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
Journal of the American Chemical Society
|June 11, 2008
まとめ
研究者らは,調整可能なn型半導体特性を有する新しいアセン型結合分子を合成した. より長い分子構造とより多くのピラジン単位は,電子の親和性と安定性を高め,電子アプリケーションの有望性を示しています.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 材料科学 材料科学とは
- 固体物理 固体物理学
背景:
- アセンの類の分子は,有機電子工学において極めて重要です.
- 安定したn型有機半導体の開発は依然として課題です.
研究 の 目的:
- ピラジン単位で結合した新しいアセンのタイプの分子を合成し,特徴づけます.
- 分子構造とn型半導体特性との関係を研究する.
- オーガニック・エレクトロニクス・アプリケーションの潜在能力を評価する.
主な方法:
- 1,2-ダイアミンと1,2-ジケトンの凝縮結合による合成.
- 顕微鏡分析 (UV-vis, 1H NMR) で分子構造と結合を決定する.
- 電子特性を評価するための電気化学分析 (循環式電圧測定法).
主要な成果:
- ピラジンを含むアセンの誘導体を成功して合成した (1-5).
- エネルギーギャップは分子長さの増加に伴い減少し,良い電子移位を示しています.
- N型特性は分子長とピラジン単位で改善され,LUMOレベルは -3.24から -3.78 eVに変化します.
- 聚合傾向は分子長さに伴い増加するが,t-ブチル群はこれを緩和する.
結論:
- これらのピラジン基アセンの誘導体は,調節可能なn型半導体特性を有しています.
- 高い電子親和性,安定性,可変性があるため,次世代有機電子機器の実現に有望である.
関連する概念動画
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Removing one hydrogen from the intervening CH2 group with both...
01:13Five-Membered Heterocyclic Aromatic Compounds: Overview
Heterocyclic aromatic compounds are cyclic compounds that are aromatic and have one or more heteroatoms—atoms other than carbon, in the ring. Depending upon the number of atoms present in the ring, they can be either five or six-membered. Examples of five-membered heterocyclic aromatic compounds include pyrrole, furan, thiophene, and imidazole. Pyrrole consists of one nitrogen atom having one lone pair of electrons. Furan and thiophene have one oxygen and one sulfur heteroatom, respectively.
01:18Aromatic Hydrocarbon Anions: Structural Overview
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous overlap of p...
Due to the absence of continuous overlap of p...
01:10Nomenclature of Aryl and Heterocyclic Amines
The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.
01:25Basicity of Heterocyclic Aromatic Amines
Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).
02:39Nomenclature of Alkynes
Alkynes are unsaturated hydrocarbons characterized by the presence of carbon-carbon triple bonds and have a general formula CnH2n-2. The nomenclature of alkynes follows a set of rules similar to alkanes and alkenes; however, alkynes bear the suffix "-yne" instead of "-ane" or "-ene." There are two approaches to naming alkynes: