Facile Single or Double C−H Bond Activation on η²-Platinum-Complexed Acetylenes by Interaction with [<i>cis</i>-PtR₂S₂] and [<i>cis</i>-PtR₂(CO)S] (R = C₆F₅, S = Thf)

The μ-hydride μ-acetylide [cis,cis-(PPh3)2Pt(μ-H)(μ-1κCα:η2-C⋮CPh)Pt(C6F5)2] (1b) and the μ-vinylidene [cis,cis-(CO)(C6F5)2Pt(μ-CCHPh)Pt(PPh3)2] (2) have been prepared by reaction of the η2-phenylacetylene Pt(0) complex [Pt(η2-HC⋮CPh)(PPh3)2] as the starting material with the disolvated [cis-PtR2S2] and the monosolvated [cis-PtR2(CO)S] (R = C6F5, S = tetrahydrofuran) complexes, respectively. Extension of these reactions to the μ-η2:η2-bis(alkyne)diplatinum(0) precursor [{Pt(PPh3)2}2{μ-η2:η2-(1,4-HC⋮C)2C6H4}] and 2 equiv of the corresponding solvated complexes affords the bis(μ-hydride) μ-diethynylbenzene [{cis,cis-(PPh3)2Pt(μ-H)Pt(C6F5)2}2{μ-1κCα:4κCα‘:η2:η2-(1,4-C⋮C)2C6H4}] (4b) and the bis(μ-vinylidene) [{cis,cis-(CO)(C6F5)2PtPt(PPh3)2}2{μ4-1κCα:2κCα:3κCα‘:4κCα‘-(1,4-CCH)2C6H4}] (3) tetranuclear derivatives. The preparation of the isomeric [{trans-(PPh3)(C6F5)Pt(μ-H)Pt(C6F5)(PPh3)}2{μ-1κCα:4κCα:η2:η2-(1,4-C⋮C)2C6H4}] (4a) was achieved by reaction of [{trans-PtH(PPh3)2}2{μ-1κCα:2 κCα‘-(1,4-C⋮C)2C6H4}] with 2 equiv of [cis-PtR2S2]. Single-crystal X-ray structural determinations of 1b, 2, 3, and 4b are reported.