852636-60-3Relevant academic research and scientific papers
Platinum(II) and palladium(II) complexes of bisphosphine ligands bearing o-N,N-dimethylanilinyl substituants: A hint of catalytic olefin hydration
Jones, Nathan D.,Meessen, Patric,Losehand, Udo,Patrick, Brian O.,James, Brian R.
, p. 3290 - 3298 (2008/10/09)
Platinum(II) and palladium(II) complexes of the potentially hexadentate P,N-donor ligand family Ar2P-X-PAr2 (X = (CH 2)2 [dmape], cyclic-C5H8 [dmapcp]; Ar = o-N,N-dimethylanilinyl) are described. In CH2Cl2, the dmape complexes exist as equilibrium mixtures of MCl2(P,P′,N- dmape) and [MCl(P,P′,N-dmape)]Cl isomers (M = Pd, Pt), governed by ΔH° = -19 ± 4 kJ mol-1 and ΔS° = -100 ± 30 J mol-1 K-1 for M = Pt, and ΔH° = -11 ± 7 kJ mol-1 and ΔS° = -60 ± 20 J mol-1 K-1 for M = Pd. The water-soluble dmapcp complexes exist solely in the [MCl(P,P′,N-dmapcp)]Cl form, but the free and coordinated anilinyl rings in these complexes are in slow diastereoselective exchange. X-ray crystal structures for MCl2(P,P′-dmape) (M = Pd, Pt), and the [PdCl(P,P′,N-dmape)]+ and [PtCl-(P,P′,N- dmapcp)]+ cations, are presented. Some of the complexes show marginal activity in water for the catalyzed hydration of maleic to malic acid, giving about 6-7% conversion in 24 h at 100°C and substrate:catalyst loadings of 100:1. Attempts to synthesize a PdCl(P,P′,N-dmapm)+ species led instead to isolation of [Pd(μ-Cl)(P,P′-dmapm)]2-[PF 6]2 (dmapm = Ar2PCH2Ar2).
