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在混合价值分子中通过键对比通过空间合:在单分子尺度上观察电子定位
Rebecca C Quardokus1, Yuhui Lu, Natalie A Wasio
1Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Journal of the American Chemical Society
|December 20, 2011
概括
扫描道显微镜揭示了两个铁分子的独特电子行为. 甲-Fe2分子在氧化后显示不对称的电荷分布,与对称的para-Fe2不同,突出了分子几何学在电子合中的作用.
科学领域:
- 有机金属化学 有机金属化学
- 表面科学是一门学科.
- 分子电子学分子电子学
背景情况:
- 研究了具有相同公式但不同几何形状的双核有机金属分子.
- 了解这些系统中的电子合对于分子电子学至关重要.
研究的目的:
- 通过扫描道显微镜 (STM) 研究meta-Fe2和para-Fe2有机金属分子的电子特性.
- 确定分子几何学如何影响混合价值物种中的电荷局部化和脱局部化.
主要方法:
- 在77K的超高真空条件下扫描道显微镜 (STM).
- 化学氧化产生混合价值物种.
- 实验性STM图像与受约束密度函数 (CDFT) 计算的比较.
主要成果:
- 无论是meta-Fe2还是para-Fe2,在它们的中性状态下都表现出对称的电子密度.
- 氧化后的meta-Fe2显示出不对称的电子状态密度,表明电荷局部.
- 氧化后的Para-Fe2保持了对称的电子状态密度,这表明电荷移位.
- CDFT的计算支持了在meta-Fe2中的电荷定位和在para-Fe2.2中的移位的实验发现.
结论:
- 这些分子中的金属中心之间的电子合主要通过有机链接器的键发生,而不是通过空间的相互作用.
- 在meta-Fe2中电荷定位是一种内在的分子性质,独立于基质或对子离子效应.
- 分子几何学决定了混合价值双核有机金属化合物中的电子合和电荷分布.
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