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Updated: Sep 11, 2025

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
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Published on: November 29, 2018

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作为多模式光开关的Norbornadiene四旋旋风:协同光和质子控制的热释放

Adil S Aslam1, Monika Shamsabadi1, Rebecca J Salthouse2

  • 1Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden.

ChemSusChem
|August 19, 2025
PubMed
概括

新的norbornadiene (NBD) 光开关提供长期的分子太阳能热能储存. 这些先进的材料可以控制能量释放,超越了以前的系统,延长了热稳定性.

关键词:
分子光开关是分子光开关.没有出生,也没有出生.质子化 质子化 质子化氨酸是什么?氨酸是什么?太阳能储能是太阳能储能的一种方式.

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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.
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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.
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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.
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