固态 (55) Mn 双---二 (IV) 的固态 (55) Mn 核磁共振光谱 (Mn) [Mn) 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O 2O
Paul D Ellis1, Jesse A Sears, Ping Yang
1Biological Sciences Division, Pacific Northwest National Laboratory, 902 Battlelle Boulevard, Richland, Washington 99352, United States, USA.
Journal of the American Chemical Society
|November 10, 2010
概括
这项研究使用NMR和理论来研究一个氧复合体. 结果显示,实验和计算的磁屏蔽和复合体的四极合常量之间有很好的一致性.
科学领域:
- 无机化学 无机化学 有机化学
- 固态化学 固态化学
- 计算化学计算化学
背景情况:
- 在二复合体中抗铁磁合对于理解磁相互作用至关重要.
- 双--二-四复合体是研究电子转移和磁性特性的模型系统.
- 固态核磁共振 (NMR) 谱学提供了有关本地电子环境的详细信息.
研究的目的:
- 描述抗铁磁 bis(μ-oxo) dimanganese(IV) 复合物的电子结构 [Mn(2) O(2) ((salpn) ((2)) ] (1).
- 为了比较实验 (55) Mn固态NMR数据与理论计算.
- 验证用于研究磁性复合体的第一原则计算方法.
主要方法:
- 在冷温度下使用 (55) Mn固态核磁共振 (NMR) 进行实验分析.
- 理论调查采用破碎对称密度函数理论 (DFT).
- 使用ZORA和PBE QZ4P函数进行全电子级理论计算.
主要成果:
- 实验 (55) Mn四极合常数 (C(Q)) 和不对称参数 (η(Q)) 分别确定为 24.7 MHz 和 0.43 .
- 对于每个Mn4+) 离子,观察到3375 ppm的显著的异性离子屏蔽贡献 (Δσ).
- 理论计算预测C(Q) 和 η(Q) 值为23.4MHz和0.68,与实验结果相一致.
结论:
- 固态NMR和第一原理理论的结合提供了一个强大的方法来表征复合体.
- 计算的电场梯度 (EFG) 准确地反映了实验NMR参数.
- 这项研究增强了对二氧系统中磁相互作用和电子结构的理解.
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