封装N-异环碳素双核过渡金属复合物作为晶体固态分子旋转的新平台
Mingoo Jin1,2, Rempei Ando1, Marcus J Jellen3
1Division of Applied Chemistry and Frontier Chemistry Center (FCC), Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
Journal of the American Chemical Society
|December 31, 2020
概括
研究人员使用N-异环碳化合物和过渡金属设计了新的晶体分子旋转器. 改变金属 (铜到黄金) 调整了旋转能量障碍和改变了固态排放特性.
科学领域:
- 材料科学
- 超分子化学
- 固态化学
背景情况:
- 晶体固体中的分子通常具有有限的移动性.
- 具有旋转元件的两极动态晶体具有可调的物理性质.
- 设计分子旋转器需要精确控制分子运动和相互作用.
研究的目的:
- 报告一项新型发射晶体分子旋转器的设计.
- 研究过渡金属对分子旋转动态的影响.
- 探索分子旋转与固态辐射之间的关系.
主要方法:
- 双核复合物的合成,其中包括一个pyrazine旋转器和N- heterocyclic carbene外.
- 加入过渡金属 (铜或金) 作为轴部件.
- 通过实验和计算方法分析分子旋转的激活能量.
- 固态发射特性及其与分子动态的相关性.
主要成果:
- 成功设计了具有可调节的旋转能量屏障的新型发射晶体分子旋转器.
- 由于硬质和电子效应,将铜换成黄金将旋转能量障碍降低了约4.0千卡/mol.
- 通过选择过渡金属来调节固态排放特性,Cu (I) 呈现红移排放.
- 在铜和金转子系统中观察到分子旋转诱导的排放火.
结论:
- 使用N-异环碳素复合物和金属中心旋转轴开发的平台是设计晶体分子旋转器的一个有希望的支架.
- 通过改变中央过渡金属,可以有效地操纵旋转动力学和固态排放.
- 这种方法为制造具有可控制动态和光物理性质的先进分子材料提供了一种多功能策略.
相关概念视频
02:58Crystal Field Theory - Octahedral Complexes
29.1K
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...
29.1K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
46.4K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
46.4K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
1.1K
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...
1.1K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.3K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.3K
02:42Valence Bond Theory
10.2K
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...
10.2K
01:18Aromatic Hydrocarbon Cations: Structural Overview
3.4K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
Removing one hydrogen from the intervening CH2 group...
3.4K