稳定的形式为零价值和二磁性单价值的和复合物,基于二二联体
P James Daff1, Michel Etienne, Bruno Donnadieu
1Laboratoire de Chimie de Coordination du CNRS, UPR 8241, 205 Route de Narbonne, 31077 Toulouse Cedex 4, France.
Journal of the American Chemical Society
|April 11, 2002
概括
这项研究通过一种新的反应合成了罕见的零价值和复合物. 这些复合体表现出意想不到的二磁性,原因是电子移位到连接体上,挑战了传统的电子结构模型.
科学领域:
- 有机金属化学 有机金属化学
- 无机化学 无机化学 有机化学
- 协调化学 协调化学
背景情况:
- 低价值过渡金属复合物的合成对于理解电子结构和反应性至关重要.
- 伪八面体的和复合物具有零价构造是罕见的,并且具有独特的电子特性.
研究的目的:
- 为了高效地合成和表征新的,正式的零价值和单价值的伪八面体和复合物.
- 为了研究这些不寻常的复合体的电子结构和磁性.
主要方法:
- 合成和复合物使用金属和1,4-diisopropyl-1,4-diaza-1,3-diene (iPr(2) -dad).
- 使用X射线晶体学和光谱学进行表征.
- 使用密度函数理论 (DFT) 的计算分析.
主要成果:
- 有效合成Nb ((iPr ((2) -dad) ((3) (52%的收益率) 和Ta ((iPr ((2) -dad) ((3) (33%的收益率).
- 在氧化过程中形成二磁单价复合物[M(iPr(2) -dad) ((3) ]][BPh ((4) ].
- DFT计算显示了强烈的t(2g) 轨道分裂,导致二磁性和电子定位在联体上.
结论:
- 正式的零价复合物最好描述为M(+) 与阴离子连接体,M(iPr(2) -dad) ((3) = M(+) iPr(2) -dad (-).
- 这种电子配置,M(+) iPr(2) -dad (-),解释了这些伪八面体的和复合体中观察到的二磁性.
- 这些发现挑战了低价值过渡金属复合物的传统电子结构模型.
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