ヘクサゴンからリボンへ サイアニドをオーバーフリップする
Andrew I Guttentag1,2, Kristopher K Barr1,2, Tze-Bin Song1,3
1California NanoSystems Institute, University of California, Los Angeles , Los Angeles, California 90095, United States.
Journal of the American Chemical Society
|December 10, 2016
まとめ
熱アニリングは,金面のサイアニド単層を六角格子からリボン構造に変換します. この再構成は振動周波数を変化させ,シアン化物/アイソシアン化物の混合結合モデルを示唆する.
科学分野:
- 表面科学
- 材料化学
- ナノテクノロジー
背景:
- Au ((111) 上のシアン化物単層は,吸収状態で六角形の密集した格子を示します.
- 新しい材料や触媒の設計には 表面再構成を理解することが重要です
研究 の 目的:
- 熱アニリング時のシアン化物単層の構造的および化学的変化を調査する.
- 再構成された単層の結合構成を解明する.
主な方法:
- 表面構造と振動モードに敏感なテクニックを使用して表面の特徴づけ.
- 構造的な変化を誘発する熱冷却.
- 振動スペクトロスコピーのデータ (例えば赤外線スペクトロスコピー) の分析.
主要な成果:
- 六角格子から混合方向の"リボン"構造への移行は,アニリング後に観察された.
- 振動周波数の重要な変化,CNの青いシフトを2235cm−1に,新しい低周波モードを145cm−1に.
- 新しい構造は,ドメインの境界線と,金基板の影響を受けた方向的にオフセットされた領域を特徴としています.
結論:
- 凝固されたシアン化物単層は,混合シアン化物/アイソシアン化物結合による新しいリボン構造を採用しています.
- 接着システムは,Au-CNとAu-NCの両方の配置を,Au ((""1) 表面に垂直に指向します.
- 観測されたスペクトルの変化は,金シアン化水晶化に似た化学環境の重要な変化を示しています.
関連する概念動画
Valence Bond Theory
11.5K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.5K
Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism
4.6K
Cyanohydrins are formed when cyanide nucleophiles and carbonyl compounds like aldehydes and ketones react. A strong base, the cyanide ion, catalyzes cyanohydrin formation. The ions are generated from HCN under aqueous conditions. Once the cyanide ions are generated, the first step involves the nucleophilic attack of the cyanide ions on the electrophilic carbonyl carbon. This attack shifts the π electrons from the C=O to the oxygen atom forming the alkoxide ion intermediate. The alkoxide anion...
4.6K
Hydrogen Bonds
135.9K
Hydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
135.9K
Hydrogen Bonds
15.7K
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
15.7K
Bonding in Metals
55.1K
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
55.1K
Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview
4.1K
Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction...
4.1K


