π-Acidity and π-basicity of N-heterocyclic carbene ligands. A computational assessment

详细信息    查看全文

• 作者：Heiko Jacobsen ; Andrea Correa ; Chiara Costabile and Luigi Cavallo
• 关键词：N-Heterocylic ligands ; Carbene ligands ; Transition metal complexes ; DFT calculations
• 刊名：Journal of Organometallic Chemistry
• 出版年：2006
• 出版时间：15 October 2006
• 年：2006
• 卷：691
• 期：21
• 页码：4350-4358
• 全文大小：330 K

文摘

In this contribution we report on a systematic analysis of the bond between transition metals and N-heterocyclic carbene (NHC) ligands. We compare the σ and π-contributions in a series of complexes in which the formal d-electron count ranges from d⁰ to d¹⁰. Our results confirm the currently accepted idea that NHC are not pure σ-donors. In the series of complexes examined here π-contribution is 10 % at least. Moreover, remarkable metal-to-ligand backdonation occurs also for d⁰ complexes, and many systems present a substantial ligand-to-metal π donation.