相关实验视频
Updated: Oct 21, 2025
07:09
Development of Efficient OLEDs from Solution Deposition
Published on: November 4, 2022
2.4K
旋转交叉复合体的不对称设计,以增加表面沉积的波动性
Miguel Gakiya-Teruya1, Xuanyuan Jiang2, Duy Le3
1Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306, United States.
Journal of the American Chemical Society
|September 2, 2021
概括
这项研究介绍了一种新型的铁复合体,表现出歇斯底里旋转过渡和光诱导的旋转状态捕获. 不对称的分子设计能够实现强大的合作性和升华,这对于薄膜应用至关重要.
科学领域:
- 协调化学
- 材料科学
- 超分子化学
背景情况:
- 旋转交叉 (SCO) 复合体对分子开关和存储器具有兴趣.
- 在上海合作组织材料中实现强大的合作性和波动性仍然是一个挑战.
- 探索不对称的分子设计以调和这些特性.
研究的目的:
- 合成和表征一个单核铁 (II) 复合体, [Fe (tBu2qsal) ].
- 调查其旋转转变性,包括歇斯底里和光诱导效应.
- 探索分子不对称性,合作性和薄膜应用的升华之间的关系.
主要方法:
- 使用三角体配体 (tBu2qsalH) 和Fe (II) 前体合成铁 (II) 复合物.
- 通过温度依赖的测量和光诱导的研究来描述旋转转变行为.
- 单晶X射线衍射和密度功能理论 (DFT) 的计算.
- 20纳米薄膜的制造和介电性质分析
主要成果:
- 复合体[Fe(tBu2qsal) 2在117K (冷却) 和129K (升温) 呈现出歇斯底里旋转转变.
- 在较低的温度下观察到光诱导的激发自旋状态的捕获.
- 该复合物易于升华,单晶通过升华生长.
- 不对称的结构,在相反的侧面有 tert-butyl 组和 quinoline 部分,促进了层叠和分子间相互作用.
- 旋转过渡被保留在20纳米薄膜中,显示出歇斯底里介电变化.
- DFT计算支持基于低旋转和高旋转状态观察到的介电变化.
结论:
- 不对称的分子设计是创建具有强大的合作性的挥发性SCO复合物的有效策略.
- [Fe(tBu2qsal) 2复合体显示了薄膜分子切换装置的潜力.
- 突出了分子结构,分子间相互作用和宏观性质之间的相互作用.
相关概念视频
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.2K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.2K
02:42Valence Bond Theory
9.9K
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...
9.9K
01:17Spin–Spin Coupling: One-Bond Coupling
1.1K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.1K
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.2K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.2K
01:08Spin–Spin Coupling Constant: Overview
1.1K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
1.1K
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