150266-85-6Relevant academic research and scientific papers
A Simple Method for the Preparation of Alkylpalladium Compounds by Pd-O Bond Cleavage in Cationic Bis(ether-phosphane)palladium(II) Complexes with Grignard Reagents
Lindner, Ekkehard,Dettinger, Johannes,Fawzi, Riad,Steimann, Manfred
, p. 1347 - 1354 (2007/10/02)
The bis(chelate) complexes O)2>2 (3a-e) react with methylmagnesium chloride with a concomitant cleavage of two weak Pd-O bonds to give the methyl complexes trans-ClPd(PO)2(CH3) (4a-e) (PO: η1-P-coordinated; PO: η2-O,P-chelated; Scheme 1).Diffusion of pentane into the reaction mixture of 4a-e in the presence of the formed magnesium salts yields the cationic complexes trans-O)-(PO)> (6a, c).The reaction of 3a-e with benzylmagnesium chloride affords the cationic benzyl complexes cis-O)(PO)> (8a-e) inwhich only one Pd-O bond has been cleaved.In the presence of carbon monoxide 4a-e and 6a, c are transformed into the corresponding acyl complexes CH3C(O)Pd(PO)2Cl (5a-e) and O)(PO)> (7a, c).Whereas at 183 K variable-temperature 31P-NMR measurements of 6a, c, 7a, c indicate a non-rigid behavior of the two differently bound ether-phosphanes, the dynamic process is frozen out for 8a-e.By a line-shape analysis of the spectra the thermodynamic parameters ΔG(excit.), ΔH(excit.), and ΔS(excit.) are obtained.According to a crystal structure analysis 3d and 6c crystallize in the monoclinic space group P21/c with Z = 4.Key Words: Palladium complexes, alkyl- and acyl- / Ether phosphanes / Fluxional behavior
Fluxional Behavior of Cationic cis-Bis(ether-phosphane)palladium(II) Complexes. - 31P-DNMR Spectroscopic Investigations, Line-Shape Analysis, and Determination of Rearrangement Barriers
Lindner, Ekkehard,Dettinger, Johannes,Mayer, Hermann August,Kuehbauch, Hartwig,Fawzi, Riad,Steimann, Manfred
, p. 1317 - 1324 (2007/10/02)
Reaction of X2Pd(PO)2 (X = Cl: 1a-g, k-n, p; X = Br: l'; X = I: k'', l'', o'') with stoichiometric amounts of AgClO4 results in the formation of the monochelate complexes cis-O)(PO)> (2a-g, k-n, p, l', l'') (PO: η1-P-coordinated; PO: η2-O,P-chelated).In the case of compounds 1o, 1k'', and 1o'', which are provided with less basic ether-phosphanes, the halide-bridged dimers O)2>22 (3o, k'', o'') are obtained.Temperature-dependent 31P-NMR spectra of the fluxional complexes 2a-g, k-n, p, l', l'' lead to ΔG(excit.)values.By using modified versions of DNMR5, computer-generated spectra of 2a, b, f, k, l, p, l', l'' were obtained and fitted to the experimental spectra.Graphic application of the Eyring equation to the kinetic data afforded the thermodynaic parameters ΔH(excit.), ΔS(excit.), and ΔG(excit.).The ΔS(excit.) values are in agreement with an associative exchange mechanism for 2a, b, f, l, p, l', l'' and with a dissociative exchange mechanism for 2k. 2k and 3o crystallize in the monoclinic and triclinic space group P21/c and P with Z = 4 and Z = 2, respectively.Key Words: Palladium complexes / Ether-phosphanes / NMR, 31P, dynamic, line-shape analysis / Fluxional behavior
