经过异常激发状态的分子内质子转移反应
Jian-Kai Wang1, Chih-Hsing Wang1, Chi-Chi Wu1
1Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China.
Journal of the American Chemical Society
|January 30, 2024
概括
这项研究探讨了新型聚黄中的硫键和激发状态的分子内质子转移 (ESIPT). 结果显示,非传统的ESIPT机制是受质子强度决定的,而不是酸度.
科学领域:
- 摄影化学
- 超分子化学
- 有机化学
背景情况:
- 与传统的OH或NHH键相比,醇键 (H键) 具有非常规的特性.
- 由于主导的nπ*特征,在醇系统中激发状态内质子转移 (ESIPT) 可能是非发射性的.
- 了解ESIPT机制的根本差异对于开发新型光发光材料至关重要.
研究的目的:
- 在一系列4'-替代-7-胺-3-黄素 (NTF) 中研究H键强度对ESIPT的影响.
- 阐明基于醇的系统中非传统的ESIPT反应背后的驱动力.
- 探索分子结构,H键特性和光物理性质之间的关系.
主要方法:
- 合成了一系列具有不同H键强度的4'-替代-7-氨基-3-黄素 (NTF).
- 用光谱分析 (UV-Vis吸收,光发射) 来表征分体发射.
- 光上转变光谱测量中SH ESIPT的速度.
主要成果:
- 合成的NTF在UV激发时表现出690-720nm之间的分体辐射.
- 试验确定H结合强度顺序:N-NTF < O-NTF < H-NTF < F-NTF
- 观察到H键强度和ESIPT速率之间的反向相关性 (F-NTF,最强的H键,显示最慢的ESIPT),与传统模型相矛盾.
- 通过碳酸氧基度的合理化结果,表明接受质子的强度控制ESIPT,而不是-SH酸度.
结论:
- 在研究的非正规H结合系统中,ESIPT反应是非常规的.
- 碳氧的质子接受能力是ESIPT的主要驱动因素,超过酸性.
- 这些发现为含有硫醇的分子中的ESIPT机制提供了新的见解,为设计先进的功能材料铺平了道路.
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