アセチレン・アンモニアコクリスタルの合成と理論的特徴付け
Roland Boese1, Dieter Bläser, Georg Jansen
1Fachbereich Chemie, Universität Duisburg-Essen, Campus Essen, Universitätsstr. 5, D-45117 Essen, Germany. roland.boese@unidue.de
Journal of the American Chemical Society
|February 10, 2009
まとめ
研究者らは,X線 difraktionを用いて,アセチレンとアンモニアで作られた,知られている最小の分子コクリスタルを育てました. この研究は,コクリスタル形成の初期段階として,安定した分子集積を明らかにしています.
科学分野:
- 固体化学 固体化学
- マテリアルサイエンス 材料科学
- クリスタログラフィーです.
背景:
- 分子共結晶は調節可能な性質を備えています.
- コクリスタル形成のメカニズムを理解することは極めて重要です.
- 小さな分子システムにはユニークな課題があります.
研究 の 目的:
- 最小の分子コクリスタルの1つを合成し,特徴づけること.
- アセチレン・アンモニアコクリスタルの構造的特徴と安定性を調査する.
- コクリスタル形成における分子集積の役割を調査する.
主な方法:
- X線微分計でのインシット結晶の成長.
- 単一結晶X線微分分析. 単一結晶X線微分分析. 単一結晶X線微分分析. 単一結晶X線微分分析. 単一結晶X線微分分析. 単一結晶X線微分分析. 単一結晶X線微分分析.
- アブ・イニシオ 計算式計算.
主要な成果:
- 1: 1のアセチレンとアンモニアの分子コクリスタルを成功裏に育てました.
- 結晶構造は,ジグザグ状の鎖の反並列層で構成されています.
- Ab initio計算は,構成要素である分子集積物の安定性を確認した.
結論:
- アセチレン-アンモニア共結晶は,共結晶形成を研究するための最小限のシステムを表しています.
- 安定した小分子集積は,コクリスタルの成長の前駆体として特定されています.
- この研究は,超分子組成の初期段階についての洞察を提供します.
関連する概念動画
01:28Structures of Carboxylic Acid Derivatives
Structure of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
02:37Structure and Physical Properties of Alkynes
Introduction:
In nature, compounds containing both carbon and hydrogen are known as "hydrocarbons". Aliphatic hydrocarbons are compounds whose molecules contain saturated single bonds (i.e., alkanes) or unsaturated double or triple bonds. Alkenes contain carbon–carbon double bonds and have a structural formula CnH2n. Unsaturated hydrocarbons containing carbon–carbon triple bonds are called "alkynes" and are structurally represented by the formula CnH2n-2.
The simplest alkyne is ethyne, or...
In nature, compounds containing both carbon and hydrogen are known as "hydrocarbons". Aliphatic hydrocarbons are compounds whose molecules contain saturated single bonds (i.e., alkanes) or unsaturated double or triple bonds. Alkenes contain carbon–carbon double bonds and have a structural formula CnH2n. Unsaturated hydrocarbons containing carbon–carbon triple bonds are called "alkynes" and are structurally represented by the formula CnH2n-2.
The simplest alkyne is ethyne, or...
01:29Preparation of Amides
Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC).
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
01:28Preparation of 1° Amines: Gabriel Synthesis
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
01:19Amines to Amides: Acylation of Amines
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
01:07Acid Halides to Amides: Aminolysis
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In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...