Nature of M-Ga Bonds in cationic metal-gallylene complexes of iron, ruthenium, and osmium, [(?5-C5H5)(L)2M(GaX)]+: a theoretical study.
Nature of M-Ga Bonds in cationic metal-gallylene complexes of iron, ruthenium, and osmium, [(?5-C5H5)(L)2M(GaX)]+: a theoretical study.
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铁、钌和锇的阳离子金属-没食子络合物中 M-Ga 键的性质，[(?5-C5H5)(L)2M(GaX)]：理论研究。
DOI：
10.1021/ic102217z
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发表时间：
2011
影响因子：
4.6
通讯作者：
Pandey KK
中科院分区：
文献类型：
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作者：
Pandey KK
在BP 86/TZ 2 P/ZORA水平上对铁、钌和锇的阳离子半夹心镓烯配合物[（η5-C5 H5）（L）2 M（GaX）]+（M = Fe，L = CO，PMe 3; X = Cl，Br，I，NMe 2，Mes; M = Ru，Os：L = CO，PMe 3; X = I，NMe 2，Mes）进行了密度泛函理论计算.计算得到的模型体系[（η5-C5 H5）（Me 3 P）2Fe（GaI）]+的几何参数与最近报道的[（η5-C5 Me 5）（dppe）Fe（GaI）]+的实验值符合得很好。这些系统中的M-Ga键比预期的单键短，这一观察结果不是由于M-Ga π轨道的贡献，而是主要由于镓的s轨道对M-Ga成键轨道的贡献。这样的发现符合本特规则的原则，因为在与（电负性更强的）亚镓基取代基X的键中发现相应更大的镓p轨道特性。与此相一致的是，发现ΔEσ是[（η5-C5 H5）（L）2 M]+和[GaX]碎片之间轨道相互作用的主要贡献（ΔEπ仅相当于总轨道贡献的8.0−18.6%）;因此GaX配体表现为主要的σ-供体配体。静电对总相互作用能Δ Einc的贡献也非常重要，其大小与相应的轨道相互作用相当（或在某些情况下甚至更大）。
Density Functional Theory calculations have been performed for the cationic half-sandwich gallylene complexes of iron, ruthenium, and osmium [(η5-C5H5)(L)2M(GaX)]+(M = Fe, L = CO, PMe3; X = Cl, Br, I, NMe2, Mes; M = Ru, Os: L = CO, PMe3; X = I, NMe2, Mes) at the BP86/TZ2P/ZORA level of theory. Calculated geometric parameters for the model iron iodogallylene system [(η5-C5H5)(Me3P)2Fe(GaI)]+are in excellent agreement with the recently reported experimental values for [(η5-C5Me5)(dppe)Fe(GaI)]+. The M−Ga bonds in these systems are shorter than expected for single bonds, an observation attributed not to significant M−Ga π orbital contributions, but due instead primarily to high gallium s-orbital contributions to the M−Ga bonding orbitals. Such a finding is in line with the tenets of Bent’s Rule insofar as correspondingly greater gallium p-orbital character is found in the bonds to the (more electronegative) gallylene substituent X. Consistent with this, ΔEσis found to be overwhelmingly the dominant contribution to the orbital interaction between [(η5-C5H5)(L)2M]+and [GaX] fragments (with ΔEπequating to only 8.0−18.6% of the total orbital contributions); GaX ligands thus behave as predominantly σ-donor ligands. Electrostatic contributions to the overall interaction energy ΔEintare also very important, being comparable in magnitude (or in some cases even larger than) the corresponding orbital interactions.