The mononuclear complexes Pt(P-P')Cl2, 1 and 2, where P-P' are the chiral ligands (S)-N-(diphenylphoshino)-2-((diphenylphosphinoxy)methyl)pyrrolidine, S-prolophos, and (R)-1-(diphenylphosphinoxy)-2-(N-ethyl-N-(diphenylphosphino)amino)butane, R-butaphos, respectively, were prepared and characterized in solution by H-1, C-13, P-31, Pt-195, and two-dimensional correlation spectra. Only one conformer is observed in solution at room temperature. The structure of complex 1, Pt{S-prolophos}Cl2, was solved by X-ray diffraction: C29H29Cl2NOP2Pt, orthorhombic, space group P2(1)2(1)2(1), a = 16.557 (6) angstrom, b = 15.697 (6) angstrom, c = 10.948 (5) angstrom, Z = 4, and V = 2845 (2) angstrom 3. The structure was was refined to a conventional R factor of 0.040 (R(w) = 0.049) for 2700 observed reflections with I > 3-sigma(I). The ligand P-P' is coordinated in an endobidentate fashion to the platinum atom, which exhibits a slightly distorted square-planar geometry. The seven-membered ring adopts a twist-boat conformation. Treatment of complexes 1 and 2 with silver tetrafluoroborate in methanol solution afforded the dinuclear species [(P-P')Pt(mu-OH)2Pt(P-P')][BF4]2 (3, P-P' = prolophos, and 4, P-P' = butaphos). The dinuclear unit is maintained even in the gas phase, as shown by the MS-FAB spectrum of complex 4. Complex 1, in the presence of tin(II) chloride, was found to catalyze the hydroformylation of styrene to (R)-(-)-2-phenylpropanal with 37% optical purity.
Mono-and dinuclear complexes of platinum(II) with chiral diphosphines: Pt(P-Pʹ)Cl2 and [Pt(P-Pʹ)(µ-OH)]2[BF4]2(P-Pʹ = prolophos, N-(diphenylphosphino)-2-((diphenylphoshpinoxy)methyl)pyrrolidine, and butaphos, 1-(diphenylphosphinoxy)-2-(N-ethyl-N-(diphenylphosphino)amino)butane). Crystal and molecular structure of Pt{S-prolophos-P, Pʹ)Cl2 / A. BANDINI, G. BANDITELLI, E. CESAROTTI, G. MINGHETTI, B. BOVIO. - In: INORGANIC CHEMISTRY. - ISSN 0020-1669. - 31:3(1992), pp. 391-398.
Mono-and dinuclear complexes of platinum(II) with chiral diphosphines: Pt(P-Pʹ)Cl2 and [Pt(P-Pʹ)(µ-OH)]2[BF4]2(P-Pʹ = prolophos, N-(diphenylphosphino)-2-((diphenylphoshpinoxy)methyl)pyrrolidine, and butaphos, 1-(diphenylphosphinoxy)-2-(N-ethyl-N-(diphenylphosphino)amino)butane). Crystal and molecular structure of Pt{S-prolophos-P, Pʹ)Cl2
A. BANDINIPrimo
;G. BANDITELLISecondo
;E. CESAROTTI;
1992
Abstract
The mononuclear complexes Pt(P-P')Cl2, 1 and 2, where P-P' are the chiral ligands (S)-N-(diphenylphoshino)-2-((diphenylphosphinoxy)methyl)pyrrolidine, S-prolophos, and (R)-1-(diphenylphosphinoxy)-2-(N-ethyl-N-(diphenylphosphino)amino)butane, R-butaphos, respectively, were prepared and characterized in solution by H-1, C-13, P-31, Pt-195, and two-dimensional correlation spectra. Only one conformer is observed in solution at room temperature. The structure of complex 1, Pt{S-prolophos}Cl2, was solved by X-ray diffraction: C29H29Cl2NOP2Pt, orthorhombic, space group P2(1)2(1)2(1), a = 16.557 (6) angstrom, b = 15.697 (6) angstrom, c = 10.948 (5) angstrom, Z = 4, and V = 2845 (2) angstrom 3. The structure was was refined to a conventional R factor of 0.040 (R(w) = 0.049) for 2700 observed reflections with I > 3-sigma(I). The ligand P-P' is coordinated in an endobidentate fashion to the platinum atom, which exhibits a slightly distorted square-planar geometry. The seven-membered ring adopts a twist-boat conformation. Treatment of complexes 1 and 2 with silver tetrafluoroborate in methanol solution afforded the dinuclear species [(P-P')Pt(mu-OH)2Pt(P-P')][BF4]2 (3, P-P' = prolophos, and 4, P-P' = butaphos). The dinuclear unit is maintained even in the gas phase, as shown by the MS-FAB spectrum of complex 4. Complex 1, in the presence of tin(II) chloride, was found to catalyze the hydroformylation of styrene to (R)-(-)-2-phenylpropanal with 37% optical purity.Pubblicazioni consigliate
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