Nickel, palladium and platinum

This report summarizes the literature from 2008 relevant to the chemistry of the group 10 transition elements. Novel coordination and organometallic compounds of these elements are presented and selected applications in the areas of catalysis, bioinorganic/medicinal chemistry are discussed

Nickel, palladium and platinum

This report summarizes the literature from 2010 relevant to the chemistry of the group 10 transition elements. Novel coordination and organometallic compounds of these elements are presented and selected applications in the areas of catalysis, bioinorganic/medicinal chemistry are discussed

Nickel, palladium and platinum

This report summarizes the literature from 2009 relevant to the chemistry of the group 10 transition elements. Novel coordination and organometallic compounds of these elements are presented and selected applications in the areas of catalysis, bioinorganic/medicinal chemistry are discussed

Synthesis and chemistry of diphenyl-2-pyridylphosphine complexes of palladium(0). X-Ray characterisation of Pd(Ph2Ppy)2(?2-DMAD) and trans-Pd(Ph2Ppy)2(PhC?CH2)(CF3CO2)

The zerovalent complexes Pd(Ph2Ppy)31 and Pd(Ph2Ppy)2(dba) 2, where Ph2Ppy is diphenyl-2-pyridylphosphine and dba = trans,trans-dibenzylideneacetone, have been synthesized and characterised. Reactions of 1 with alkynes have been studied and the dimethyl acetylenedicarboxylate complex Pd(Ph2Ppy)2(η2-DMAD) 3, where DMAD is dimethyl acetylenedicarboxylate, isolated and structurally characterised. The complexes trans-Pd(Ph2Ppy)2(PhC[double bond, length half m-dash]CH2)X, X = CF3CO2−4 or Cl−5, and trans-Pd(Ph2Ppy)2{CO(CH3)C[double bond, length half m-dash]CH2}Cl 6 result from oxidative addition of phenylacetylene/CF3CO2H, phenylacetylene/Et3NHCl and methacryloyl chloride respectively to 1, and the crystal structure of 4 is presented. The alkenyl ligand is bound to palladium through the α carbon in 4. Insertions into the M–C bond of the vinyl complexes have been studied. No isolable insertion product is obtained with carbon monoxide although the complex is active for the catalytic alkoxycarbonylation of phenylacetylene to 2-phenylpropenoate. Propadiene inserts into the Pd–C bond in 4 to give the cationic π-allyl complex [Pd(Ph2Ppy)2{η3-C3H4C(Ph)[double bond, length half m-dash]CH2}][CF3CO2] 7. The complex Pd(Ph2Ppy)3 is found to catalyse the vinylation of Ph2Ppy to the corresponding 2-propenylphosphonium trifluoromethanesulfonate

Synthesis and characterisation of benzyl phosphino-thioether and -thiolato Pd(II) complexes and their applications in Suzuki coupling reactions

The synthesis of the benzyl phosphinothioether derivatives Ph2PCH2CH(Et)SR and their corresponding palladium complexes are reported, where R = CH2Ph (3), R = CH2Ph (3), R = CH2-3,5-Me-C6H3 (4) and R = 1-CH2C10H7 (5). Crystallographic data obtained for the complexes Pd(3)Cl-2 and Pd(4)Cl-2 show intra- and inter-molecular pi-pi interactions between the aromatic rings on the P and S substituents, and NOE experiments for Pd(4)Cl-2 show that these interactions persist in solution. The performance of the phosphinothioether palladium complexes in aryl-aryl cross-coupling reactions is compared with that of the corresponding complex of the parent phosphinothiolato ligand Ph2PCH2CH(Et)S- (1). High turnover numbers up to 2000000 are reported for the coupling of bromobenzene, using the palladium dimer [Pd(1)I](2) as the catalyst precursor. Kinetic studies show a linear dependence of the reaction on catalyst loading. The effect of other variables on the cross-coupling reaction, such as temperature, solvent and base, is also reported

Chiral silver and gold rings: synthesis and structural, spectroscopic, and photophysical properties of Ag and Au metallamacrocycles of bridging NHC ligands

The synthesis and silver(I) and gold(I) coordination chemistry of a new chiral, bidentate N-heterocyclic carbene (NHC) dehydrohexitol derivative (3) are reported. The imidazolium salt [H23][PF6]2 reacts with Ag2O and Au(tht)Cl (tht = tetrahydrothiophene) precursors to form the isostructural 18-membered metallamacrocyclic dimers [Ag2(μ-3)2][PF6]2 and [Au2(μ-3)2][PF6]2 and the monocarbene complex [(AuCl)2(μ-3)]. Single-crystal X-ray structures have been determined for the bis-imidazolium precursor [H23][PF6]2 and corresponding Ag(I) and Au(I) complexes of ligand 3. Comparison between the X-ray-derived structures and solution-phase NMR data for [Ag2(μ-3)2][PF6]2 and [Au2(μ-3)2]- [PF6]2 demonstrate that the complexes adopt a conformation in solution different from that found in the solid state, implying a conformational flexibility of the metallamacrocycle in solution. Both [(AuCl)2(μ-3)] and [Au2(μ-3)2][PF6]2 are emissive in the solid state at ca. 380 nm (λex = 295 nm). Time-resolved luminescence measurements indicate different excited-state lifetimes for the two species, with [(AuCl)2(μ-3)] measured at 35 ns and [Au2(μ-3)2][PF6]2 at 379 ns. The chiroptical properties of the silver and goldNHCcomplexes have been studied by circular dichroism (CD)