稳定的平面六基电子六基N-异环碳具有可调节的电子性质
Carsten Präsang1, Bruno Donnadieu, Guy Bertrand
1UCR-CNRS Joint Research Chemistry Laboratory (UMR 2282), Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
Journal of the American Chemical Society
|July 21, 2005
概括
玻拉碳类似物具有很高的热稳定性. 研究人员可以通过改变为中心的替代物来精确调整它们的电子性质,同时保持类似的硬质体积.
科学领域:
- 无机化学 无机化学 无机化学
- 有机金属化学 有机金属化学
背景情况:
- 玻拉是具有独特电子性质的异环化合物.
- 碳类型提供了一种途径来修改分子框架的电子和硬质特征.
研究的目的:
- 为了研究博拉的碳类型的合成和特性.
- 探索这些新型化合物中电子性质的可调性.
主要方法:
- 新型玻拉碳类型的合成.
- 谱学表征 (NMR,IR,UV-Vis) 进行.
- 计算研究 (DFT) 用于分析电子结构.
主要成果:
- 合成的碳类型显示出极好的热稳定性.
- 电子属性,如HOMO-LUMO间隙和电荷分布,通过在原子上的不同替代物成功调整.
- 同类产品的绝缘形状在很大程度上保持一致,从而促进了直接的电子比较.
结论:
- 玻拉的碳类型是热稳定化合物的有前途的类别.
- 精确的电子调可以通过中心的替代剂修改来实现.
- 这些发现为设计具有定制电子特征的材料开辟了道路.
相关概念视频
Electron Configuration of Multielectron Atoms
The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the 3s orbital, giving a 1s22s22p63s1 configuration. The electrons occupying the outermost shell orbital(s) (highest value of n) are called valence electrons, and those occupying the inner shell orbitals are called core electrons. Since the core electron shells correspond to noble gas electron configurations, we can abbreviate electron...
Nuclear Stability
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together in the...
To hold positively charged protons together in the...
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...
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
Atomic Nuclei: Nuclear Spin
All atomic particles possess an intrinsic angular momentum, or 'spin'. Electrons, protons, and neutrons each have a spin value of ½, although protons and neutrons in nuclei may have higher half-integer spins owing to energetic factors.
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not contribute to...
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not contribute to...
Induced Electric Dipoles
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...


