Bimetallic Cluster Complexes: The Synthesis, Structures, and Bonding of Ruthenium Carbonyl Cluster Complexes Containing Palladium and Platinum with the Bulky Tri-<i>tert</i>-butyl-phosphine Ligand

The bis-phosphine compounds M(PBut3)2, M = Pd and Pt, readily eliminate one PBut3 ligand and transfer MPBut3 groups to the ruthenium−ruthenium bonds in the compounds Ru3(CO)12, Ru6(CO)17(μ6-C), and Ru6(CO)14(η6-C6H6)(μ6-C) without displacement of any of the ligands on the ruthenium complexes. The new compounds, Ru3(CO)12[Pd(PBut3)]3, 10, and Ru6(CO)17(μ6-C)[Pd(PBut3)]2, 11, Ru6(CO)17(μ6-C)[Pt(PBut3)]n, n = 1 (12), n = 2 (13), and Ru6(CO)14(η6-C6H6)(μ6-C)[Pd(PBut3)]n, n = 1 (15), n = 2 (16), have been prepared and structurally characterized. In most cases the MPBut3 groups bridge a pair of mutually bonded ruthenium atoms, and the associated Ru−Ru bond distance increases in length. Fenske−Hall calculations were performed on 10 and 11 to develop an understanding of the electron deficient metal−metal bonding. 10 undergoes a Jahn−Teller distortion to increase bonding interactions between neighboring Ru(CO)4 and Pd(PBut3) fragments. 11 has seven molecular orbitals important to cluster bonding in accord with cluster electron-counting rules.双膦化合物M(PBut3)2（其中M为钯（Pd）和铂（Pt））可轻松脱去一分子三叔丁基膦（PBut3）配体，并将MPBut3基团转移至Ru3(CO)12、Ru6(CO)17(μ6-C)以及Ru6(CO)14(η6-C6H6)(μ6-C)中的钌-钌键上，且不会置换该钌配合物上的任何配体。本研究已成功合成并完成结构表征的新型化合物包括：Ru3(CO)12[Pd(PBut3)]3（编号10）、Ru6(CO)17(μ6-C)[Pd(PBut3)]2（编号11）、Ru6(CO)17(μ6-C)[Pt(PBut3)]n（n=1时对应化合物12，n=2时对应化合物13），以及Ru6(CO)14(η6-C6H6)(μ6-C)[Pd(PBut3)]n（n=1时对应化合物15，n=2时对应化合物16）。多数情况下，MPBut3基团会桥连一对相互成键的钌原子，且对应的Ru-Ru键键长会有所增加。我们针对化合物10和11开展了Fenske-Hall计算（Fenske-Hall），以深入阐释其缺电子金属-金属成键机制。化合物10会发生姜-泰勒（Jahn-Teller）畸变，以增强相邻Ru(CO)4与Pd(PBut3)片段间的成键相互作用。化合物11拥有7个对团簇成键至关重要的分子轨道，这一结果符合团簇电子计数规则。