电荷状态,可变性和磁性的相互作用在类似分子的Au25(SR) 18集群中
Sabrina Antonello1, Neranjan V Perera, Marco Ruzzi
1Department of Chemistry, University of Padova , via Marzolo 1, 35131 Padova, Italy.
Journal of the American Chemical Society
|October 4, 2013
概括
这项研究阐明了金纳米集群Au25(SR)18.18.的电化学和磁性. 新的发现与最近的文献相矛盾,提供了对不同电荷状态的行为的一致的理解.
科学领域:
- 纳米材料 化学 化学
- 电化学 电化学 电化学
- 频谱学是一种光谱学.
- 计算化学计算化学
背景情况:
- 类似分子的金纳米集群,如Au25(SR) 18,表现出独特的电化学和光学特性.
- 最近的文献提出了对Au25(SR) 18属性的相互矛盾的描述,需要进一步调查.
- 了解电荷状态依赖的行为对于它们的应用至关重要.
研究的目的:
- 为了阐明Au25的电化学动力学和重组能量(SR) 18减少和氧化.
- 在中性和氧化状态下研究Au25(SR) 18的磁性特性.
- 调和实验发现与有关电子结构和磁性的理论预测.
主要方法:
- 单分散Au25(SR) 18(0) 的合成.
- 在受控条件下的循环电压测量,以确定电子转移动力学和重组能量.
- 连续波电子磁共振 (cw-EPR) 谱学用于研究磁性.
- 密度函数理论 (DFT) 对光学吸收光谱和电子结构的计算.
主要成果:
- 已建立的电子转移速率常数和Au25(SR) 18氧化还原过程的重组能量.
- 已证明化学不可逆性,可降解为Au25(SR)18(2-) 和氧化为Au25(SR)18(2+) /Au25(SR)18(3+).
- 提供了令人信服的证据,表明Au25 ((SR) 18 ((+) 是二磁性,与最近的报道相矛盾.
- DFT计算准确地复制了实验光学光谱和能量差距变化与电荷状态.
- 揭示了阴阳物种中HOMO水平的显著分裂,限制了超原子模型的适用性.
结论:
- 这项研究提供了Au25(SR) 18属性的自相一致的图像,作为电荷状态的函数.
- 这些发现挑战了最近对Au25(SR) 18的氧化还原和磁性行为的解释.
- 该方法为理解类似分子的金纳米集群提供了一个蓝图.
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