在高旋转铁中由质子介导的电子配置变化(II) 氨酸酸盐
Chuanjiang Hu1, Bruce C Noll, Charles E Schulz
1Department of Chemistry and Biochemistry, University of Notre Dame, Indiana 46556, USA.
Journal of the American Chemical Society
|October 27, 2005
概括
研究人员用imidazolate连接物合成和表征铁 (II) 酸盐. 它们的电子结构,通过Mössbauer光谱学研究,显著不同于伊米达结合类型,为这些化合物提供了新的模型.
科学领域:
- 无机化学 无机化学 有机化学
- 材料科学 材料科学 材料科学
- 频谱学是一种光谱学方法.
背景情况:
- 铁酸盐在生物系统和催化过程中至关重要.
- 了解铁复合物的电子结构是预测其反应性的关键.
- 区分imidazolate和imidazole在铁中结合的酸盐对于微调性质很重要.
研究的目的:
- 为了合成和描述新型的五坐标高旋转伊米达酸结合铁 (II) 酸盐.
- 研究和比较伊米达酸结合与伊米达结合铁的电子结构.
- 为这些不同类型的化合物开发精确的电子结构模型.
主要方法:
- 合成五坐标高旋转伊米达酸结合铁 (II) 酸.
- 在强磁场中使用Mössbauer光谱法来确定电子结构.
- 对光谱数据的比较分析与类似的伊米达结合系统进行比较.
主要成果:
- 成功合成和表征了两个新的铁 (II) 酸盐复合物.
- 莫斯巴乌尔光谱显示,与意达酸结合铁酸相比,与意达结合铁酸有不同的电子结构.
- 开发了电子结构模型,解释了观察到的差异.
结论:
- 五坐标高旋转意达酸结合铁的电子结构与意达结合的类似物显著不同.
- 莫斯巴乌尔光谱是一种强大的工具,用于探测铁复合体中的微妙电子差异.
- 开发的模型为理解和设计相关的铁酸盐系统提供了一个框架.
相关概念视频
Ions and Ionic Charges
In ordinary chemical reactions, the nucleus — which contains the protons and neutrons of each atom and thus identifies the element — remains unchanged. Electrons, however, can be added to atoms by transfer from other atoms, lost by transfer to other atoms, or shared with other atoms. The transfer and sharing of electrons among atoms govern the chemistry of the elements. During the formation of some compounds, atoms gain or lose electrons to form electrically charged particles called ions.
Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Colors and Magnetism
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 eye.
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 eye.
Ionic Association
The ionic association is the association of oppositely charged ions in an electrolyte solution to form ion pairs. Bjerrum defined ion pairs as two oppositely charged ions whose electrostatic attraction exceeds the thermal energy of the system, typically expressed as 2kT. Electrostatic attraction depends on ionic charge, separation distance, and the dielectric constant of the medium. Thermal energy, represented by kT, reflects the tendency of ions to move independently due to molecular motion.
The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...


