A comparative computational study of cationic coinage metal-ethylene complexes (C2H4)M(+) (M=Cu, Ag, and Au)
A comparative computational study of cationic coinage metal-ethylene complexes (C2H4)M(+) (M=Cu, Ag, and Au)
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DOI：
10.1021/jp953064i
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发表时间：
1996-07-25
影响因子：
--
通讯作者：
Schwerdtfeger, P
中科院分区：
文献类型：
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作者：
Hertwig, RH;Koch, W;Schwerdtfeger, P
阳离子 (C2H4)M(+) 配合物（M = Cu、Ag 和 Au）已通过不同的从头算分子轨道、密度泛函 (DFT) 和密度泛函/Hartree-Fock (DFT/HF) 混合方法进行了检查，使用相对论有效核心势酸（一种准相对论方法来解释相对论效应）。对于 (C2H4Au+) 观察到相当大的相对论稳定，使得计算的结合能几乎是 (C2H4Ag+) 的两倍，并且仍然显着高于 (C2H4Cu+)。在不同计算级别获得的结构特征和能量学，尽管它们的计算需求显着不同，但彼此满足一致性，增加了可归因于计算经济的 DFT 和 DFT/HF 混合方法的置信度。为了确定对于这些 (C2H4)M(+) 配合物中的键合性质，对于所有三种金属阳离子，与乙烯的相互作用显示出较大的共价贡献，其中大部分来自配体对金属的 σ 供体贡献，而 pi 受体键合（反向键合）则不太重要。对于 (C2H4Au+ 和 (C2H4Cu+)，而 (C2H4Ag+ 是 T 形的。
The cationic (C2H4)M(+) complexes (M = Cu, Ag, and Au) have been examined by different ab initio molecular orbital, density functional (DFT), and density functional/Hartree-Fock (DFT/HF) hybrid methods using relativistic effective core potentials acid a quasi-relativistic approach to account for relativistic effects. For (C2H4Au+ a substantial relativistic stabilization is observed, such that the computed binding energies are almost twice as high than for (C2H4Ag+ and still significantly higher than for (C2H4Cu+. Structural features and energetics obtained at the various computational levels, although they differ significantly in their computational demands, are in satisfying agreement with each other, adding to the level of confidence that can be attributed to the computationally economic DFT and DFT/HF hybrid methods. In order to determine the nature of the bonding in these (C2H4)M(+) complexes, an energy decomposition scheme is applied to the DFT results. For all three metal cations, the interaction with ethylene shows large covalent contributions. The major part of the covalent terms stems from sigma-donor contribution from the ligand to the metal, whereas pi-acceptor bonding (back-bonding) is less important. An atoms-in-molecules (ATM) analysis of the charge density distribution reveals cyclic structures for (C2H4Au+ and (C2H4Cu+, whereas (C2H4Ag+ is T-shaped.