ボロンニトリドナノシートの酸素基の機能化
Toby Sainsbury1, Amro Satti, Peter May
1Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin, Ireland. toby.sainsbury@gmail.com
Journal of the American Chemical Society
|October 30, 2012
まとめ
ヒドロキシル群を備えた,共振的に機能した六角性ボロン・ニトリドナノシート (BNNSs) を合成した. これらの改造されたBNNSは,改善された界面結合を通じて,ポリマーナノコンポジットの機械的性質を高めました.
科学分野:
- マテリアルサイエンス 材料科学
- ナノテクノロジー ナノテクノロジー
- 表面化学について
背景:
- 六角性ボロン・ニトリドナノシート (BNNS) はユニークな性質を有していますが,高度なアプリケーションでは表面の修正が必要です.
- 共同的機能化は,BNNSの特性を調整し,複合材料への統合を改善するための重要な戦略です.
研究 の 目的:
- BNNSsのための新しい共性化学機能化の方法を開発する.
- ハイドロキシル機能化されたBNNSs (OH-BNNSs) を2段階の酸素根のアプローチで合成する.
- ポリマーナノ複合材料の機械特性に対するOH-BNNSの影響を調査する.
主な方法:
- h-BN格子におけるボロン原子の溶液相酸素基の機能化.
- アルコキシ基の2段階の接合に続いて,OH-BNNSsを生成するために,水解性非機能化が行われます.
- HR-TEM,ラマン,UV-vis,FTIR,NMR,TGAを用いた特徴付けを行いました.
主要な成果:
- アルコキシ群の成功コヴァレンツ接合と,その後BNNSsでヒドロキシル群の形成.
- OH-BNNSsで調製されたポリマーナノ複合物の強化された機械的性質の実証.
- 複合材料の性能に対する共振的および非共振的界面結合の影響の分析.
結論:
- BNNSsの共性機能化のための堅牢な方法が確立され,OH-BNNSsが得られました.
- ハイドロキシル機能化されたBNNSは,ポリマーナノ複合物の機械的性質を大幅に改善します.
- この研究は,ナノフィルラー-ポリマー複合材料の性能を決定する際のインターフェイス結合の重要な役割を強調しています.
関連する概念動画
03:08Hydroboration-Oxidation of Alkenes
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
02:55Exceptions to the Octet Rule
Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:
02:36Regioselectivity and Stereochemistry of Hydroboration
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
02:47Alkynes 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.
02:54Lewis Structures of Molecular Compounds and Polyatomic Ions
To draw Lewis structures for complicated molecules and molecular ions, it is helpful to follow a step-by-step procedure as outlined:
02:15Preparation of Alcohols via Addition Reactions
Overview
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...