摘要
The synthesis and X-ray structure analysis of the carbodiphosphorane (CDP) complexes [Hg{C(PPh3)2}2][Hg2I 6] and [Cu{C(PPh3)2}2]I are reported. The cations [Hg{C(PPh3)2}2] 2+ and [Cu{C(PPh3)2}2]+ have approximately linearly coordinated metal atoms. Quantum chemical calculations of model compounds bearing N-heterocyclic carbene (NHC) ligands, [M(NHC)2] and [M{C(PH3)2}2] (M = Cu+, Ag+, Au+, Zn2+, Cd 2+, Hg2+), have been carried out at the BP86/TZ2P level. The metal-ligand bonds are very strong, and the bond dissociation energies exhibit a V-shaped trend for first-, second-, and third-row transition metals: Ag+ < Cu+ < Au+ and Cd2+ < Zn2+ < Hg2+. The investigation of the bonding situation in the complexes using an energy decomposition analysis shows that the metal-ligand bonding comes mainly from electrostatic attraction. Inspection of the orbital interactions shows that the Mq←(NHC)2 and Mq←{C(PH3)2}2 σ donation provides between 65 and 75% of the total orbital interactions ΔE orb. The contribution of the Mq→(NHC)2 and Mq→{C(PH3)2}2 π back-donation is very weak. The nature and strength of the donor-acceptor bonds of the two-electron donor ligand NHC and the four-electron donor ligand CDP with the group 11 and group 12 metal cations are very similar.
源语言 | 英语 |
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页(从-至) | 3330-3339 |
页数 | 10 |
期刊 | Organometallics |
卷 | 30 |
期 | 12 |
DOI | |
出版状态 | 已出版 - 27 6月 2011 |
已对外发布 | 是 |