导电的非指数长度依赖性在化物终结的单分子道连接中
Limin Xiang1,2, Thomas Hines1, Julio L Palma1,2
1Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University , Tempe, Arizona 85287, United States.
Journal of the American Chemical Society
|December 24, 2015
概括
奇怪的是,质中的分子导电率会随着长度的增长而偏离指数式衰变. 这种非指数行为归因于电极的分子结合几何变化,而不仅仅是道.
科学领域:
- 分子电子
- 凝聚物质物理
- 材料科学
背景情况:
- 分子电导率通常会随着长度的增加而呈指数的下降,这表明非共振道.
- 对于分子电子学来说,了解长度依赖导电性至关重要.
研究的目的:
- 为了研究结的寡二烯的长度依赖分子导电性.
- 阐明从指数衰变观察到的偏差的潜在导电机制.
主要方法:
- 通过对不同长度的寡烯分子进行导电性测量.
- 过渡电压光谱检测道障碍
- 进行X射线光电子光谱和拉伸长度测量.
- 模拟分子行为的理论计算.
主要成果:
- 随着分子长度的增加,氧基的导电率呈非指数性下降.
- 没有温度依赖证实了道作为主要的导电机制.
- 过渡电压光谱显示了道屏障的长度依赖性下降.
- 射线光电子光谱和理论计算确定了结合几何上的转变为非指数长度依赖的原因.
结论:
- 聚乙烯与电极的结合几何显著影响分子导电.
- 分子连接的非指数长度依赖性可能来自结构变化,而不仅仅是电子效应.
- 这一发现为分子系统中的电荷传输提供了新的见解.
相关概念视频
Debye–Huckel–Onsager Conductance Equation
185
The Debye-Hückel-Onsager equation is a cornerstone of physical chemistry, providing a method to determine the molar conductance (Λm) and molar conductance at infinite dilution (Λ°m) for uni-univalent electrolytes.Uni-univalent electrolytes are electrolytes that dissociate in solution to produce one cation with a +1 charge and one anion with a –1 charge per formula unit.This equation addresses two crucial phenomena: the asymmetry effect and the electrophoretic effect.
185
Theory of Strong Electrolytes
87
The interionic forces of the strong electrolytes depend on the solvent's dielectric constant, which is the ability of a solvent to store electrical energy, based on its polarizability. and the solution's concentration. In high-dielectric solvents and in dilute solutions, weak electrostatic forces keep ions apart. However, in low-dielectric solvents or concentrated solutions, stronger interionic forces may cause ions to pair up as ionic doublets despite being fully ionized. The theory of strong...
87
Electrical Conductivity
2.0K
In perfect conductors, the electric field inside is always zero due to the abundance of free electrons, which nullify any field by flowing. As a result, any residual charge resides on the surface.
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
2.0K
Kohlraush’s Law and its Applications
95
Kohlrausch's law explains that at infinite dilution, where dissociation is complete, each ion's contribution to the conductivity of the electrolyte is independent of the nature of other ions present in the solution. It also implies that when an electrolyte is highly diluted, the conductance of the electrolyte is the sum of the individual conductances of the ions it generates upon dissociation. The quantity of electricity an ion carries is proportional to its molar ionic conductance, which...
95
Ostwald’s Dilution Law
105
Consider a binary electrolyte AB with a concentration ‘c’ that reversibly dissociates into its constituent ions. The degree of this dissociation is represented by ⍺. This means that the equilibrium concentration of each ionic species can be expressed as ⍺c. As well as this, the fraction of the electrolyte that remains undissociated at equilibrium is given by (1−⍺). The corresponding equilibrium concentration for this undissociated portion is then calculated...
105
Electrical Transport
112
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...
112


