含有Ca-Fe或Yb-Fe键的异金属复合物: [M{CpFe(CO) 2}2(THF) 3 2 (M = Ca或Yb) 的合成和分子和电子结构
Matthew P Blake1, Nikolas Kaltsoyannis, Philip Mountford
1Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
Journal of the American Chemical Society
|September 6, 2011
概括
重土和稀土金属与铁复合物形成直接的金属-金属键. 铁键比铁键更短,更强,与化合物不同.
科学领域:
- 有机金属化学 有机金属化学
- 无机化学 无机化学 无机化学
- 固态化学 固态化学
背景情况:
- 新型金属-金属键的合成和表征对于理解化学结合至关重要.
- 研究重土金属和双价稀土金属与有机金属化合物的反应性,可以了解它们的电子性质.
研究的目的:
- 合成和描述具有或与铁之间直接金属-金属键的新型化合物.
- 为了比较-铁和-铁键的结合特性和结构性质.
- 为了研究与相同铁前体的反应,并比较结果.
主要方法:
- 通过合金反应合成金属金属结合化合物.
- 单晶X射线衍射用于结构确定.
- 密度函数理论 (DFT) 计算,包括齐格勒-劳克,分子轨道和原子在分子分析.
主要成果:
- 合成了同结构化合物[MFp{2}{THF}{3}}{2} (M = Ca或Yb),其中包括直接的M-Fe键 (Ca-Fe: 3.0185{6} Å,Yb-Fe: 2.9892{4} Å).
- DFT的计算证实了较短的Yb-Fe距离,并表明主要是静电M-Fe粘合.
- Yb-Fe 键表现出比 Ca-Fe 键更大的相互作用能量和键临界点电子密度.
- 反应形成MgFp{2}{THF}{4}没有直接的Mg-Fe键.
结论:
- 在Ca/Yb和铁之间可以实现直接的金属-金属键,而Yb-Fe键比Ca-Fe键更强,更短.
- M-Fe的结合主要是静电的,由计算分析支持.
- 具有不同的反应性,形成O结合的复合体,而不是直接的金属-金属键.
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