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复合体中的古典与桥接基联体:溶剂的作用
Stephen C Chmely1, Christin N Carlson, Timothy P Hanusa
1Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235-1822, USA.
Journal of the American Chemical Society
|April 23, 2009
概括
类合物复合物通常通过西格玛键结合. 然而,在没有协调基的情况下,pi结合的形式更稳定,这是一个新的双核复合体表现出阴离子-pi相互作用的证据.
科学领域:
- 有机金属化学 有机金属化学
- 计算化学计算化学
- 材料科学 材料科学 材料科学
背景情况:
- 类合物复合物通常与西格玛结合的配体合成,被认为是它们最稳定的配置.
- 在没有协调溶剂或基的情况下,类合物复合物的电子和结构偏好仍然不太清楚.
研究的目的:
- 在没有协调基的情况下,研究类合物复合物的首选结合方式.
- 通过计算和实验验证与pi结合的类复合物的稳定性.
主要方法:
- 密度函数理论 (DFT) 的计算被用来建模不同类合物结合模式的电子结构和稳定性.
- 进行了一种新型,未溶解的双核复合物的合成和分离,[Mg{C(3) ((SiMe(3)) ((2) H(3) }] ((2),进行了.
主要成果:
- DFT计算预测,在没有协调基的情况下,与pi键结合的基连接体在能量上比与西格玛键结合的连接体更受青.
- 合成的双核复合体具有桥接基联体的特征,证实了在未溶解条件下对pi-bonding的预测.
- 该结构揭示了中心和联体的pi系统之间显著的阴离子-pi相互作用.
结论:
- 这项研究挑战了长期以来的西格玛结合假设,认为它是类基复合物的独家首选模式.
- 未溶解的类复合物有利于pi-bonding,通过分子内阴离子-pi相互作用稳定,为有机化学提供了新的见解.
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