Facile single or double c-h bond activation on η2-platinum-complexed acetylenes by interaction with [cis-PtR2S2 and [cis-PtR2(CO)S] (R = C6F5,S= Thf)

The mu-hydride mu-acetylide [cis,cis-(PPh3)(2)Pt(mu-H)(mu-1kCalpha: eta(2)-CdropCPh)Pt(C6F5)(2)] (1b) and the mu-vinylidene [CiS,CiS-(CO)(C6F5)(2)Pt(mu-C=CHPh)Pt(PPh3)(2)] (2) have been prepared by reaction of the eta(2)-phenylacetylene Pt(0) complex [Pt(eta(2)-HCdropCPh)(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 mu-eta(2): eta(2)-bis(alkyne)diplatinum(0) precursor [{Pt(PPh3)(2)}(2){mu-eta(2):eta(2)-(1,4-HCdropC)(2)C6H4}] and 2 equiv of the corresponding solvated complexes affords the bis(mu-hydride) mu-diethynylbenzene [1cis,cis(PPh3)(2)Pt(mu-H)Pt(C6F5)(2)}(2){mu-1kC(alpha):4kC(alpha'): eta(2):eta(2)-( 1,4-CdropC)(2)C6H4}] (4b) and the bis(mu-vinylidene) [{cis,cis-(CO)(C6F5)(2)PtPt(PPh3)(2)}(2){mu(4)-1kC(alpha):2kC(alpha):3kC(alpha'):4kC(alpha')-(1,4-C=CH)(2)C6H4}] (3) tetranuclear derivatives. The preparation of the isomeric [{trans-(PPh3)(C6F5)Pt(mu-H)Pt(C6F5)(PPh3)}(2){mu-1kC(alpha):4kC(alpha): eta(2):eta(2)-(1,4-CdropC)(2)C6H4}] (4a) was achieved by reaction of [{trans-PtH(PPh3)(2)}(2){mu-1kC(alpha):2 kC(alpha')-(1,4-CdropC)(2)C6H4}] with 2 equiv of [cis-PtR2S2] - Single-crystal X-ray structural determinations of 1b, 2, 3, and 4b are reported.