Reversible formation of [P{sub 2}PtH]{sub 2} platinum(I) complexes from cis-P{sub 2}PtH{sub 2} complexes, where P{sub 2} is a chelating phosphine
- Lawrence Berkeley Lab., CA (United States)
Several platinum cis-dihydride phosphine complexes, (diphos)PtH{sub 2} [4, diphos = iPr{sub 2}P(CH{sub 2}){sub 2}PiPr{sub 2} (dippe); 5, diphos = Cy{sub 2}P(CH{sub 2}){sub 2}PCy{sub 2} (dcype); and 6, diphos = tBu{sub 2}P(CH{sub 2}){sub 2}PtBu{sub 2} (dtbpe)], have been found to be unstable in solution, reversibly losing H{sub 2} and forming binuclear complexes of the general formula [(P-P)Pth]{sub 2}. The extent of dimerization in solution is directly related to the steric size of the phosphine ligand, larger phosphines imparting kinetic stability to the cis-dihydride monomers. The dimeric complexes possess terminal hydride ligands on the basis of their IR spectra; however, the room-temperature {sup 1}H, {sup 31}P({sup 1}H), and {sup 195}Pt({sup 1}H) NMR spectra show equivalence within the sets of H, Pt, and P nuclei, indicating that the dimers are fluxional in solution. This fluxional process can be stopped at low temperature for the (dippe) and (dcype) derivatives, 1 and 2, but not for the (dtbpe) derivative, 3. The complex 1 crystallizes in the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} in a cell of dimensions a = 9.245(2) A, b = 16.966(2) A, c = 22.690(6) A, and Z = 4. 22 refs., 10 figs., 8 tabs.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 41836
- Journal Information:
- Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 14 Vol. 117; ISSN JACSAT; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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