分子伝導性:アンカー群の化学的傾向

San-Huang Ke¹, Harold U Baranger, Weitao Yang

¹Department of Chemistry, Duke University, Durham, North Carolina 27708-0354, USA.

Journal of the American Chemical Society

|December 2, 2004

まとめ

分子伝導性は,アナーリング原子 (S,Se,Te) と接触構造に依存する. 伝導性は一般的に原子番号の増加とともに減少しますが,連絡先の詳細は,特に低バイアスでは,この傾向を変更することができます.

科学分野:

凝縮物質物理学凝縮物質物理学
材料科学材料科学とは
量子化学とは,量子化学である.

背景:

分子伝導性を理解することは,ナノスケールの電子機器にとって非常に重要です.
固定原子とコンタクト幾何学の選択は,電子伝送に大きな影響を与えます.
第一原理の計算は,分子電子特性を予測するために不可欠です.

研究の目的:

硫黄,セレニウム,テルリウムを固定する原子とベンゼンの分子伝導率を計算する.
コンタクト構造,鉛の方向性,吸収部位が導電性に与える影響を調査する.
導電性の化学的傾向を固定原子の原子番号に基づいて決定する.

主な方法:

分子電子構造のための密度関数理論 (DFT).
電子伝送計算のためのグリーン関数法.
リラックスした原子構造,鉛の方向性,吸附部位を考慮する.

主要な成果:

分子伝導性は,吸収部位,鉛の方向,および局所的な接触構成に非常に敏感です.
フラットコンタクトの場合,導電性は,固定原子 (S, Se, Te) の原子数を増すにつれて減少します.
この傾向は,小さなバイアスでの接触原子構成によって変化するが,大きなバイアスでは回復する.

結論:

固定原子の原子番号は,分子導電性の重要な要因ですが,唯一の決定因子ではありません.
原子規模のコンタクト構造の正確な制御は,分子電子機器のチューニングに不可欠です.
第一原理シミュレーションは,分子輸送を制御する要因の複雑な相互作用に関する貴重な洞察を提供します.

さらに関連する動画

08:43

Effect of Bending on the Electrical Characteristics of Flexible Organic Single Crystal-based Field-effect Transistors

Published on: November 7, 2016

06:44

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Published on: March 24, 2018

関連する概念動画

03:37

Molecular Shape and Polarity

Dipole Moment of a Molecule

03:05

Acid Strength and Molecular Structure

Binary Acids and Bases
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...

02:28

Electrophiles

This lesson explains the definition, classification, and characteristic features of an electrophile that are key features of nucleophilic substitution reactions. An analysis of their charge and orbital picture helps understand their reactivity for seeking electrons. Electrophiles can be classified into positive and neutral species. Other classes include free radicals and polar functional groups.
While a positive electrophile, like a proton, reacts due to its vacant, low-energy 1s orbital, the...

01:23

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.

01:27

π 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...

01:29

Induced Electric Dipoles

A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...

関連する実験動画