对于净原子键解离的阳离子效应,高价值伊米多复合体的自由能量
Nadia G Léonard1, Teera Chantarojsiri2, Joseph W Ziller1
1Department of Chemistry, University of California, Irvine, California 92697, United States.
Journal of the American Chemical Society
|January 18, 2022
概括
来自充电功能的本地电场可以调整酶和表面反应. 这项研究表明,虽然离子电荷显著改变pKa和还原潜力,但它对复合体中N-H键解离自由能量 (BDFE) 的影响很小.
科学领域:
- 无机化学 无机化学
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
背景情况:
- 当地电场影响生物和表面系统中的反应性.
- 分子系统中的充电功能可以产生电场.
- 盐化物复合物是研究反应性的相关模型.
研究的目的:
- 为了研究变化的离子电荷对 ((V) 盐酸化物复合物的特性的影响.
- 确定电荷如何影响pKa,还原潜力 (E1/2) 和N-H键解离的自由能量 (BDFE).
- 评估充电功能的实用性,以调节电子,质子和原子转移.
主要方法:
- 合成 ((V) 盐酸化物复合物,附上含有各种子 (Na+,K+,Ba2+,Sr2+,La3+,Eu3+) 的冠乙烯单元.
- 确定短暂的imido复合体的pKa值.
- 测量的降解潜力 (VI/V).
- 在酸中计算N-H BDFEs.
主要成果:
- 这系列的复合体跨越了4个充电单位.
- 在整个系列中观察到广泛的pKa值 (>9单位) 和还原潜力 (>700 mV).
- 尽管存在这些变化,但N-H BDFE仍然相对不变,仅占~6 kcal/mol.
结论:
- 结合阴离子功能的方法是调整降解潜力和pKa值的有效策略.
- 这种方法允许对这些参数进行广泛的调制,同时保持稳定的BDFE.
- 这一发现对于控制催化系统中电子,质子和原子转移途径至关重要.
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