33971-07-2Relevant academic research and scientific papers
(Phenylalkyl)palladium complexes containing β-hydrogen atoms: Synthesis and characterization of [PdR2(dppe)], [PdR(SPh)(dppe)] (R = CH2CH2Ph, CH2CH2CH2Ph, CH2CHMePh), and [Pd(CH2CH2CH2Ph)X(dppe)] (X = I, Br, Cl)
Spaniel, Thomas,Schmidt, Harry,Wagner, Christoph,Merzweiler, Kurt,Steinborn, Dirk
, p. 2868 - 2877 (2007/10/03)
Reactions of HgR2 (R = CH2CH2Ph, 1a; CH2CH2CH2Ph, 1b; CH2CHMePh, 1c) (prepared from HgCl2 and the requisite Grignard compounds) with lithium in toluene afforded (phenylalkyl)lithium compounds LiR (2a-c) in yields of between 64 and 81%. At -30 °C, they react with [PdCl2(dppe)] [dppe = 1,2-bis(diphenylphosphanyl)ethane] yielding bis(phenylalkyl)palladium(II) complexes [PdR2(dppe)] (3a-c) which were isolated (Tdec = 159 °C, 3a; 80 °C, 3b; 145 °C, 3c) and fully characterized by 1H, 13C, and 31P NMR spectroscopy. Single-crystal X-ray diffraction of [Pd(CH2CH2Ph)2(dppe)] (3a) showed that the palladium atom is square-planar coordinated by two 2-phenylethyl ligands and the dppe ligand. The two CH2CH2Ph ligands exhibite nearly a fully staggered conformation. Overall, a good approximation for the complex is that it has C2 symmetry with the C2 axis defined by the Pd atom and the midpoint of the central C-C bond of the dppe ligand. Bis(phenylalkyl)palladium complexes 3a and 3b reacted with PhSH in a 1:1 ratio yielding [PdR(SPh)(dppe)] (R = CH2CH2Ph, 5a; CH2CH2CH2Ph, 5b), whereas in the case of complex 3c, besides [Pd(CH2CHMePh)(SPh)(dppe)] (5c), a considerable amount of [Pd(SPh)2(dppe)] (6a) was formed. Reactions of 3b with the less acidic alkanethiols iPrSH and tBuSH resulted in the formation of [Pd(CH2CH2CH2Ph)(SR′)(dppe)] (R′ = iPr, 5d; tBu, 5e) along with smaller amounts of [Pd(SR′)2(dppe)] (6) and [Pd(dppe)2] (7). Furthermore, complex 3b was found to react in THF with disulfides R′SSR′ (R· = Ph, Bz, Me), yielding [Pd(CH2CH2CH2Ph)(SR′)(dppe)] (R′ = Ph, 5b; Bz, 5f, Me, 5g) with small amounts (3-13%) of [Pd(SR′)2(dppe)] (6) as side products. The corresponding reaction with MeSe-SeMe afforded [Pd(CH2CH2CH2Ph)(SeMe)(dppe)] (8a) and 3% of [Pd(SeMe)2(dppe)] (9a) and [Pd(dppe)2] (7). Reactions of complex 5b with MeI and H2C=CHCH2Br in tetrahydrofuran and with neat H2C=CHCH2Cl readily proceeded at -30 °C to give halo(3-phenylpropyl)palladium complexes [Pd(CH2CH2CH2Ph)X(dppe)] (X = I, 10a; Br, 10b; Cl, 10c). They were isolated as pale yellow powdery/microcrystalline substances and fully characterized by 13C and 31P NMR spectroscopy. Solutions of complexes 10 in THF decompose rapidly above -30 °C. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Synthesis and characterisation of mono- and binuclear palladium and platinum complexes with organochalcogenides
Singhal, Anshu,Jain, Vimal K.,Varghese, Babu,Tiekink, Edward R.T.
, p. 190 - 196 (2008/10/08)
Mononuclear palladium and platinum complexes of the type M(ER)2(P∩P) [M = Pd or Pt; ER = SPh, SC6H4Cl-4, SC6H4Me-4, SC6F5, SePh, TeC6H4OEt-4; P∩P = dppm or dppe] have been prepared and their ability to form dinuclear metal species has been demonstrated. All complexes have been characterised by multinuclear magnetic resonance (1H, 13C, 77Se, 195Pt) spectral data. The effects of phosphine ligands and organochalcogenides are reflected in the 77Se and 195Pt NMR shifts. The shielding of 195Pt NMR chemical shifts has been interpreted in terms of their binding ability to platinum. The structures of two derivatives, namely [Pd(SC6F5)2(dppe)] and [Pd(SePh)2(dppe)], have been established by X-ray crystallography. The palladium atom in each of the monomeric structures exists in a square planar geometry.
