由水染色体电子转移引起的光放松
1Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
Journal of the American Chemical Society
|July 11, 2014
概括
水中的光激发7H-氨酸通过从水中转移电子来放松,这是一个未知的途径. 这与9H-氨酸不同,揭示了分子光放松机制的新见解.
科学领域:
- 摄影化学的使用.
- 分子动力学分子动力学
- 量子化学 是一个量子化学.
背景情况:
- 分子光放松对于发光和光稳定性等特性至关重要.
- 无辐射放松通常涉及由于核几何变化的状态交叉.
研究的目的:
- 为了研究9H-腺素和7H-腺素在水中的光放松机制.
- 阐明电子转移在7H-氨酸的放松路径中的作用.
主要方法:
- 使用了激发状态的非adiabatic动力学模拟.
- 运用了代数图形构造 (ADC) 方法进行计算.
主要成果:
- 9H-腺因放松遵循通过核几何扭曲的典型途径.
- 通过从水中转移电子诱导的新型状态交叉发生7H-腺因放松.
- 在水中发现了7H-腺因的前所未有的反应途径.
结论:
- 这项研究揭示了7H-腺因中一种新的光放松机制,涉及水-染色体电子转移.
- 这一发现对理解有机电子中的激子放松有意义.
- 需要进一步的计算和实验研究来评估这种水诱导的电子转移机制的流行程度.
相关概念视频
Photosystem II
59.8K
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
59.8K
The Z-Scheme of Electron Transport in Photosynthesis
12.6K
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...
12.6K
The Photochemical Reaction Center
4.4K
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
4.4K
Photosystem I
52.7K
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...
52.7K
Photochemical Electrocyclic Reactions: Stereochemistry
1.4K
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
1.4K
Deactivation Processes: Jablonski Diagram
2.2K
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
2.2K


