The terminal phosphine groups at the tungsten bisphosphine alkyne complex [Tp*W(CO)(I)(η²-C,C′-Ph₂PC₂PPh₂)] (2) {Tp* = hydridotris(3,4,5-trimethylpyrazolyl)borate} were selectively oxidized by common methods to form the alkyne complexes 2EE (E = O, S) with either two phosphine oxide or two phosphine sulfide substituents. The respective mono-oxidized analogues 2E (E = O, S) were obtained by subjecting the already oxidized intermediates [Tp*W(CO)(I)(η²-C,C′-Ph₂P(E)C₂H)] 1E (E = O, S) to a late-stage phosphine introduction at the complex template. These modulations of the peripheral alkyne moiety have a clear impact on the redox potential of the metal-based oxidation altering the W(II/III) potential by +0.1 V on average per oxidized phosphine. In contrast to the comparable redox behavior of 2O and 2S, the coordination behavior of these complex ligands differs substantially. XRD studies show that complex 2 and the sulfide 2S act either as a P,P’- or P,S-chelate ligand leading to the dinuclear complexes [(2)PdCl₂], 3, and [(2S)PdCl₂], 3S. In contrast, the corresponding PdCl₂ complex of the monoxide 2O is connected by the free phosphine group and the W-bonded iodide as a μ²-bridging ligand leaving the phosphine oxide pending. A similar binding mode was found for the trinuclear gold complex [(2)₂Au][PF₆] (5-PF₆). Furthermore, these findings explain the undesired outcome in the reaction of [Pd(NCMe)₄][BF₄]₂ with two equivalents of 2, which resulted in the iodide abstraction product [(2)PdI₂] (4).

中文翻译：

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逐步P-氧化对W-双-双膦炔复合配体的配位和氧化还原行为的影响

在终端膦基团的双膦钨炔复杂[TP * W（CO）（I）（η ² - C，C '-Ph ₂ PC ₂ PPH ₂）]（2）{TP * =氢化三（3,4-，通过常规方法将5-三甲基吡唑基硼酸酯}选择性氧化，以形成具有两个氧化膦或两个氧化膦取代基的炔配合物2EE（E = O，S）。相应的一氧化类似物2E（E = O，S）通过使所述已氧化的中间体[TP * W（CO）得到的（I）（η ² - C，C '-Ph ₂ P（E）C ₂ ħ ）] 1E（E = O，S）引入复杂模板的后期膦中。外围炔烃部分的这些调节对基于金属的氧化的氧化还原电势具有明显的影响，从而使每个氧化的膦平均将W（II / III）电势平均+0.1 V改变。与2O和2S的可比氧化还原行为相反，这些复杂配体的配位行为存在显着差异。XRD研究表明，复杂2个硫化物2S起作用或者作为P，P” -或P，小号螯合物配体导致双核配合物[（2）的PdCl ₂ ]，3，和[（2S） PdCl ₂ ]，3S。与此相反，相应的PdCl ₂复合物中的一氧化碳的2O被自由膦基团和W键合的碘连接为μ ² -bridging配体离开氧化膦悬而未决。对于三核金络合物[（2）₂ Au] [PF ₆ ]（5 -PF ₆）发现了相似的结合模式。此外，这些发现解释了[Pd（NCMe）₄ ] [BF ₄ ] ₂与两个当量2的反应的不良结局，该结果产生了碘化物抽象产物[[2）PdI ₂ ]（4）。