具有八个超原子电子的原子精确纳米集群中的发光和电子动力学
在PubMed上查看摘要
概括
此摘要是机器生成的。具有相似核心的金纳米集群,[Au25[-SR]18-和[Au13[-dppe]5Cl2]3+,表现出不同的排放特性. 这项研究使用实验和理论方法揭示了它们的光动力学和激发状态寿命的差异.
科学领域
- 材料科学
- 纳米技术
- 物理化学
背景情况
- 黄金纳米集群 ([Au<sub>25</sub>(SR) <sub>18</sub>]<sup>-</sup>和[Au<sub>13</sub>(dppe) <sub>5</sub>Cl<sub>2</sub><sup>3+</sup>) 分享了一个13个原子的二元面核和一个8个电子的超原子配置.
- 尽管结构相似,但它们的光发光和时间解析电子动态存在显著差异.
- 了解这些差异对于设计具有定制光学特性的纳米集群至关重要.
研究的目的
- 阐明[Au<sub>25</sub>(SR) <sub>18</sub><sup>-</sup>和[Au<sub>13</sub>(dppe) <sub>5</sub>Cl<sub>2</sub><sup>3+</sup>纳米团的发射特性中的相似性和差异.
- 首次理论研究了Au<sub>13</sub>的光动力学特性.
- 将观察到的辐射行为与电子结构和衰变途径相关联.
主要方法
- 对光发光和光发光衰变的实验测量.
- 时间解析的短暂吸收光谱.
- 对辐射和非辐射衰变特性和寿命的时间依赖密度函数理论 (TD-DFT) 计算.
主要成果
- [Au<sub>13</sub>(dppe) <sub>5</sub>Cl<sub>2</sub>]<sup>3+</sup>表现出一个强烈的发射峰值,与[Au<sub>25</sub>(SR) <sub>18</sub><sup>-的较弱双模发光不同.
- 两种纳米集群的强度发射状态来自S<sub>1</sub>去激发,具有微秒寿命.
- 高兴状态在[Au<sub>13</sub>(dppe) <sub>5</sub>Cl<sub>2</sub>]<sup>3+</sup>具有较短的寿命 (<1 ps) 相比于[Au<sub>25</sub>(SR) <sub>18</sub><sup>-</sup>由于空置轨道之间的能量差距较小.
结论
- 电子结构,特别是退化无人轨道之间的能量差距,决定了这些金纳米集群的兴奋状态动态和辐射特性.
- 在理解光物理过程方面,TD-DFT计算有效地补充实验数据.
- 这项研究提供了黄金纳米集群结构属性关系的基本见解,指导了未来的材料设计.
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