吸収された分子内の単一結合の方向転換は,電子をトンネル化することによって行われます
Jörg Henzl1, Konrad Boom, Karina Morgenstern
1Abteilung für Atomare und Molekulare Strukturen (ATMOS), Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstr. 2, D-30167 Hannover, Germany.
Journal of the American Chemical Society
|July 31, 2013
まとめ
スキャントンネル顕微鏡では,分子構成の変化を正確に制御できます. この研究では,振動刺激により,金属表面上の二酸化ヒドロキシアゾブンゼンのOH群の回転が可能になり,分子操作の重要なステップであることが示されています.
科学分野:
- 表面科学とは,地表科学のことである.
- 分子操作による分子操作です.
- ナノテクノロジー ナノテクノロジー
背景:
- スキャニング・トンネル顕微鏡 (STM) は,電子トンネルを介して分子操作を可能にします.
- 振動刺激による分子内変化の制御は難しい.
研究 の 目的:
- STMを用いた精密な分子操作を実証する.
- 4,4'-ジヒドロキシヤゾーベンゼンにおける構造変化を調査する.
主な方法:
- 4,4'-ジヒドロキシヤゾーベンゼンをAu111) とAg111) の表面に吸収する.
- STMにおける非弾性電子トンネリングを利用して,分子振動を刺激する.
- STMを介して分子方向転換を観察する.
主要な成果:
- 分子構造の正確な制御が実証されています.
- OHエンドグループがC-O結合の周りを回転することを容易にした.
- 分子内の水素原子の方向転換を達成した.
結論:
- トンネリング電子による振動刺激は,分子構成を正確に制御することができます.
- 分子内の構造変化の究極の限界を達成した.
- この技術は,ナノスケール分子工学の新しい可能性を提供します.
関連する概念動画
02:38Valence Bond Theory and Hybridized Orbitals
According to valence bond theory, a covalent bond results when: (1) an orbital on one atom overlaps an orbital on a second atom, and (2) the single electrons in each orbital combine to form an electron pair. The strength of a covalent bond depends on the extent of overlap of the orbitals involved. Maximum overlap is possible when the orbitals overlap on a direct line between the two nuclei.
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
02:06Newman Projections
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
01:27π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...
02:35Molecular Orbital Theory I
Overview of Molecular Orbital Theory
03:51Molecular Orbital Theory II
Molecular Orbital Energy Diagrams
01:24π Molecular Orbitals of 1,3-Butadiene
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...