72207-39-7Relevant academic research and scientific papers
The reaction of alkynes with triangulo-clusters [Pt3(μ-CO)3(PR3)3]
Ros, Renzo,Tassan, Augusto,Roulet, Raymond,Duprez, Virginie,Detti, Serena,Laurenczy, Gabor,Schenk, Kurt
, p. 2858 - 2863 (2007/10/03)
The reaction of the cluster complexes [Pt3(μ-CO)3(PR3)3] (PR3 = PPh3 1, PPh2Bz 2, PCy3 3 and PiPr3 4) with dialkyl acetylenedicarboxylate, R′O2CC≡CCO2R′ (R′ = CH3 or tBu) have been examined under various conditions. At low temperature the alkyne reacts quantitatively giving the unstable adducts [Pt3(CO)3(PR3)3(μ3-alk yne)]. The stereochemistry of the intermediate [Pt3(CO)3(PPh3)3(μ3- tBuO2CC≡CCO2tBu)] 5has been deduced from low temperature 195pt-{1H}, 31P-{1H} and 13C-{1H} NMR spectra. At higher temperature a fluxional process renders two of the three platinum atoms equivalent on the NMR timescale. At room temperature the alkynes convert the starting clusters 1-4 to the stable dinuclear complexes [Pt2(CO)2(PR3)2(μ-R'O2 CC≡CCO2R′)] (R′ = CH3, PR3 = PPh3 6; R = tBu, PR3 = PPh3 7; PPh2Bz 8; PCy3 9 and PiPr3 10) in which the alkyne coordination has the C-C bond collinear with the Pt-Pt bond (6 and 7) or perpendicular to the Pt-Pt axis (9 and 10). The stereochemistry of these two types of dinuclear complexes has been established by NMR and IR studies and confirmed by X-ray diffraction analyses of 8 and 9.
