在聚烯 (p-phenylene) 中的一致电子传输
1Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yatacho, Yamato-Koriyama, Nara, 639-1080, Japan. matsuura@chem.nara-k.ac.jp.
Journal of molecular modeling
|June 13, 2025
概括
兴奋剂导电聚合物 (如聚烯) 增强导电性. 然而,单分子电荷传输与散装行为不同,在分子水平上显示出独特的电子性质.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 计算化学计算化学
背景情况:
- 导电性聚合物,如聚乙烯 (PPP),在散装材料中表现出极子和双极子.
- 这些充电状态在单分子连接处的行为并未得到充分理解,尽管从散装性质的潜在偏差.
研究的目的:
- 为了研究电荷状态 (中性,激素离子,二离子) 和单个基 (p-phenylene) 分子连接中的导电性之间的关系.
- 为了比较单分子电荷传输机制与散装聚合物的行为.
主要方法:
- 使用密度函数理论 (DFT) 为几何优化进行第一原则计算.
- 非平衡格林函数 (NEGF) -DFT方法与QuantumATK用于跨金电极的连贯电子传输计算.
- 使用特定函数 (B3LYP,PBE) 和基数组 (6-31G(d,p),DZP,SZP) 为准确性.
主要成果:
- 随着兴奋剂的使用,观察到显著的导电性增强 (激素阴离子和二离子状态).
- 在单一的oligophenylene (p-phenylene) 连接处的电荷运输机制与散装预期有很大差异.
- 突出了分子和散装系统之间的电子特性差异.
结论:
- 与散装导电聚合物相比,单分子结点表现出不同的电荷传输机制.
- 这项研究强调了在结合系统中考虑分子级电子特性的重要性.
- 第一原理计算为分子电子学中充电状态的行为提供了宝贵的见解.
相关概念视频
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.3K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.3K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.8K
01:34The Z-Scheme of Electron Transport in Photosynthesis
10.0K
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...
10.0K
01:27Photosystem I
61.9K
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
61.9K
01:11P-N junction
485
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
485
01:27π Electron Effects on Chemical Shift: Overview
1.1K
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,...
1.1K