プロピレン酸化物のポリメリゼーションのための高活性,同型コバルト触媒です.
Kathryn L Peretti1, Hiroharu Ajiro, Claire T Cohen
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA.
Journal of the American Chemical Society
|August 18, 2005
まとめ
新しいコバルト複合体 (サルフ) CoOAcは,ラセミックプロピレン酸化物の同型ポリメリゼーションを効率的に触媒化する. この発見は,エポキシドからステレオレギュラーポリマーを生産するための触媒的方法の進歩です.
科学分野:
- ポリマー化学のポリマー化学について
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
背景:
- プロピレン酸化物のポリメリゼーションは,ポリエーテルを生産するために不可欠です.
- プロピレン酸化物のポリメリゼーションにおける同特異性を達成することは,依然として課題です.
- コバルト複合体は,エポキシドポリメリゼーションの触媒として知られています.
研究 の 目的:
- ラセミックプロピレン酸化物の同型ポリメリゼーションのための新しい触媒を発見すること.
- エポキシドポリメリゼーションにおけるコバルト複合体の触媒活性と選択性を調査する.
主な方法:
- コバルト複合体の合成と特徴: (サルフ) CoOAc, サルフ=N,N'-ビス (3,5-ディ-テルト-ブチルサリシリジン-1,2-ベンゼンダイアミン).
- ラックプロピレン酸化物のポリメリゼーションにおけるコバルト複合体の触媒性能の試験.
- ポリマーのステレオ化学を分析して,同特異性を決定する.
主要な成果:
- コバルト複合体 ((sulph) CoOAc) は,ポリメリゼーションにおいて高い活性を示した.
- 触媒は,ラセミックプロピレン酸化物の同型ポリメリゼーションを可能にしました.
- ポリメリゼーションのステレオ化学的結果は,触媒によって制御された.
結論:
- 異種性プロピレン酸化物のポリメリゼーションのための高度に活性で選択的なコバルト触媒が特定されました.
- この触媒は,ステレオレギュラーポリプロピレン酸化物の合成のための有望な経路を提供します.
- この発見は,制御されたポリマー合成のための高度な触媒の開発に寄与する.
関連する概念動画
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
Radical Formation: Homolysis
A bond is formed between two atoms by sharing two electrons. When this bond is broken by supplying sufficient energy, either two electrons can be taken up by one atom forming ions by the cleavage called heterolysis, or the two electrons are shared by two atoms, with one each creating radicals by the cleavage called homolysis.
Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...


