在电子基态中对光诱导电子旋转极化进行金属离子控制
Martin L Kirk1,2, David A Shultz3, Ju Chen1
1Department of Chemistry and Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131-0001, United States.
Journal of the American Chemical Society
|July 12, 2021
概括
染色体根复合体中的金属离子控制着电子旋转极化 (ESP). 复合体表现出弱的发射ESP,而复合体表现出强的吸收ESP,这是由于旋转轨道相互作用.
科学领域:
- 摄影化学
- 旋转化学
- 材料科学
背景情况:
- 染色基复合体表现出光诱导的电子旋转极化 (ESP).
- 这些复合体的电子基态双子 (S0/D0) 受金属离子的影响.
- 有机激素如氧化 (NN) 是关键成分.
研究的目的:
- 研究金属离子 (Pd与Pt) 的变化如何影响光感应ESP的信号和强度.
- 了解这些复合体中排放与吸收ESP背后的机制.
- 将旋转极化现象与电子过渡和旋转轨道合相关联.
主要方法:
- 合成 (bpy) M ((CAT-m-Ph-NN) 复合物,其中 M = PdII和 PtII.
- 使用可见光对复合体进行光刺激.
- 用于检测和量化电子自旋偏振的光谱分析.
主要成果:
- 在光激发时,Pd和Pt复合体都形成了电荷分离的双重激发状态 ( 2 S 1).
- 对复合物 (1-Pd) 观察到弱发射ESP.
- 在复合体中产生强烈的吸收ESP (1-Pt).
结论:
- 金属离子标识显著控制ESP的类型和大小.
- 零场分裂影响了复合体中的过渡.
- 复合体中的旋转轨道相互作用对于产生强烈的吸收ESP至关重要.
相关概念视频
03:02Colors and Magnetism
12.6K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.6K
03:06The Pauli Exclusion Principle
56.7K
The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that contains three pieces of information:
56.7K
01:03Atomic Nuclei: Nuclear Spin State Overview
1.3K
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
1.3K
01:27π Electron Effects on Chemical Shift: Overview
1.3K
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,...
1.3K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.0K
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
2.0K
02:58Crystal Field Theory - Octahedral Complexes
28.6K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
28.6K