有机-无机混合铁弹性材料的结合驱动设计,具有可逆光异构化
Luis Verissimo1, Zi-Luo Fang2, Wei-Jian Xu1,2
1Department of Chemistry & CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal.
Inorganic chemistry
|January 23, 2025
概括
研究人员使用双有机策略设计了新的光响应性铁弹性晶体. 一个晶体表现出增强的铁弹性特性和更高的相位过渡温度由于结合,使先进的功能应用.
科学领域:
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
- 固态化学 固态化学
背景情况:
- 光响应性铁弹性材料结合了光诱导的机械和领域特性,为先进的功能材料提供了潜力.
- 有机-无机混合晶体由于其可调节的结构和特性,是这种应用的有希望的候选者.
研究的目的:
- 理性地设计和合成新的有机-无机混合体铁弹性晶体,具有量身定制的光响应和铁弹性特性.
- 研究双有机分子设计和键对相变和铁弹性行为的影响.
主要方法:
- 合成了两个新的混合铁弹性晶体: (MA) (((Me4N) [Fe(CN) 5NO) ] (1) 和 (MA) ((Me3NOH) [Fe(CN) 5NO) ] (2).
- 使用温度依赖测量的相位转换的表征.
- 通过红外 (IR) 光谱学分析光诱导异构化.
主要成果:
- 晶体2与晶体1 (138和242K) 相比,具有更高的铁弹性相变温度 (328K),这归因于增强的结合.
- 晶体2显示显著更大的自发应变 (0.153) 和11%的热诱导的尺寸变化沿着b轴.
- 这两种化合物都在N结合和O结合状态之间表现出可逆的,光诱导的酸结合异构化.
结论:
- 双有机分子设计策略,特别是将基组用于键,有效地增强了铁弹性特性和热稳定性.
- 在这些混合晶体中,光响应性异构化与强大的铁弹性相结合,为节能执行和自适应设备创建了一个多功能平台.
- 这些发现为为先进应用开发下一代可调节混合材料铺平了道路.
相关概念视频
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
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
1.8K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.3K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.3K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.0K
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.
2.0K
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
3.0K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.0K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.0K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.0K
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
8.3K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
8.3K