![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
ピリジン付属の亜鉛クロロフィール誘導体の二重ヘリックス
Yoshinao Shinozaki1, Gary Richards, Keizo Ogawa
1College of Science and Technology, Nihon University, 1-18-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308, Japan.
Journal of the American Chemical Society
|March 26, 2013
まとめ
研究者らは,亜鉛塩ロフィルの誘導体を用いて自己組み立て構造を調査した. この複合体は,溶液中の周期性オリゴーマーと,固体中の二重鎖の螺旋性ポリマーを形成した.
科学分野:
- 超分子化学 超分子化学
- 協調化化学について
- マテリアルサイエンス 材料科学
背景:
- 自己組み立ては,複雑な分子構造の構築に不可欠です.
- 亜鉛クロロフィルの誘導体は,ユニークな光物理的および構造的特性を有しています.
- 自己組み立て行動を理解することは,新しい機能的材料を設計する鍵です.
研究 の 目的:
- ピリジン付属の亜鉛クロロフィール誘導体の自己組み立て行動を調査するために.
- 溶液と固体状態で形成された構造を特徴付ける.
- ピリジンの置換剤が自己組み立てに及ぼす影響を解明する.
主な方法:
- プロトン核磁気共鳴 ((1) H NMR) スペクトロスコーピー,拡散オーダースペクトロスコーピー (DOSY),蒸気圧オスモメトリー (VPO) を用いた溶液研究.
- 単結晶X線 difraktionによる固体構造分析.
- オリゴマーの特徴化のための質量スペクトロメトリー (コールドスプレーイオン化).
主要な成果:
- 亜鉛複合体は,クロロフォームム溶液で循環性オリゴーマーを形成した.
- (1) H NMR,DOSY,VPO,および質量スペクトロメトリーからの証拠は,溶液相オリゴメリゼーションを確認しました.
- 単結晶X線解析により,固体状態で二重鎖の螺旋協調ポリマーが形成されていることが明らかになった.
結論:
- ピリジン付属の亜鉛塩ロフィルの誘導体は,固体状態と溶液状態の異なる自己組み立て行動を示しています.
- 溶液相自己組成は周期性オリゴーマーを生じ,固体組成は螺旋的な協調ポリマーを生成する.
- この研究は,この亜鉛塩ロフィルの誘導体の多様な超分子構造を形成する際の汎用性を強調しています.
関連する概念動画
01:34The Z-Scheme of Electron Transport in Photosynthesis
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...
01:15The Antenna Complex
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency can...
01:22Photosystem II
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
01:32Photosystems
Photosystems are multiprotein complexes that form the functional units of photosynthesis in plants, algae, and cyanobacteria. They are found embedded in the membrane of tiny sac-like structures called thylakoids placed inside the chloroplast.
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
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...
01:27Photosystem I
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...