24833-61-2Relevant articles and documents
Structure and Reactivity of Titanium/Platinum and Palladium Heterobinuclear Complexes with μ-Methylene Ligands
Ozawa, Fumiyuki,Park, Joon Won,Mackenzie, Peter B.,Schaefer, William P.,Henling, Lawrence M.,Grubbs, Robert H.
, p. 1319 - 1327 (1989)
A series of titanium/platinum and palladium heterobinuclear μ-methylene complexes has been prepared: M=Pt, X=Cl, L=PMe3 (2b), PMe2Ph (2c), PMePh2 (2d); M=Pt, X=Me, L=PMe2Ph (2e, 2f); M=Pd, X=Cl, L=PMe3 (2g).The μ-CH2/μ-Cl complex 2c crystallizes in the monoclinic system in space group P21/n (No. 14), with a=13.249(3) Angstroem, b=11.646(3) Angstroem, c=14.542(5) Angstroem, β=114.45(2) deg, V=2042.6(10) Angstroem3, Z=4, and density =1.87 g cm-3.The μ-CH2/μ-CH3 analogue 2e is isostructural to 2c and also crystallizes in space group, P21/n (No.14) with a=13.333(4) Angstroem, b=11.686(2) Angstroem, c=14.351(2) Angstroem, β=115.03(2) deg, V=2026.0(8) Angstroem3, Z=4, and density=1,82 g cm-3.Structural studies indicate the following: (1) the Ti-CH2 bond possesses residual double-bond character, (2) there is a dative Pt --> Ti interaction, which may be regarded as ? back-donation from the platinum atom to the Ti=CH2 group, and (3) the μ-CH3 group in 2e is bound to the titanium atom through a three-center, two-electron agostic bond.Complexes 2c and 2d react with tertiary phosphines to give Cp2(Cl)TiCH2Pt(Me)L2 species, which form μ-(C,O)-ketene complexes Cp2(Cl)TiOC(=CH2)Pt(Me)L2 upon carbonylation.The palladium complex 2g undergoes a reductive elimination reaction to give Cp2Ti(Et)Cl and Pd0PMe3 complexes.
A multinuclear NMR study of asymmetrically coordinated η3-allyls in [PtCl(η3-allyl)(phosphine)] and [Pt(phenyl)(η3-allyl)(phosphine)] complexes
Clark, Howard C.,Hampden-Smith, Mark J.,Ruegger, Heinz
, p. 2085 - 2093 (2008/10/08)
The title complexes were prepared and fully characterized by multinuclear (1H, 31P, 13C, 195Pt) NMR methods. The 1H NMR resonances of the allyl groups were unequivocally assigned by using a combination of one- and two-dimensional NMR spectroscopic techniques. The spectroscopic data have been interpreted in terms of contributions of asymmetric η1-η2-allyl bonding modes to the more familiar symmetrical η3-allyl arrangement. The relative orientation and extent of the asymmetric η1-η2-bonding were shown to be markedly dependent upon the nature of the other ligands coordinated to platinum. On prolonged standing in chloroform solution, the title complexes rearranged to give the known complexes [X(R3P)Pt(μ-Cl)]2 and trans-XClPt(PR3)2 (X = Cl, Ph). Conversion of the allyl moiety to propene gas was shown by 1H NMR and gas chromatographic analysis.
