One of the major reasons for studying chemical kinetics is to use measurements of the macroscopic properties of a system, category: chiral-oxygen-ligands, such as the rate of change in the concentration of reactants or products with time.In a article, mentioned the application of 538-58-9, Name is 1,5-Diphenylpenta-1,4-dien-3-one, molecular formula is C17H14O
Bis-chelated palladium(II) complexes with nitrogen-donor chelating ligands are efficient catalyst precursors for the CO/styrene copolymerization reaction
A series of dicationic bis-chelated palladium(II) complexes [Pd(N-N)2][X]2 (N-N = 2,2?-bipyridine (bipy), 1,10-phenanthroline (phen), and their substituted derivatives; X = PF6-, BF4-, OTf-, OTs-) has been synthesized and completely characterized both in the solid state and in solution. The synthetic procedure involves a simple one-pot reaction between Pd(MeCOO)2 and [(N-N)H][X]. These compounds are very active precatalysts for the CO/ styrene copolymerization yielding perfectly alternating polyketones. The crystal structures of some complexes of the series provide evidence that a distorsion from the ideal square planar geometry toward a twist conformation occurs. In DMSO solution, one of the two nitrogen-donor ligands is involved in a dissociative equilibrium yielding a monochelated complex with two cis coordination sites available for the copolymerization catalytic process. The catalytically active species is very stable in 2,2,2-trifluoroethanol, where its activity was found unaltered for at least 48 h of reaction without apparent decomposition to palladium metal. The addition of 1,4-benzoquinone (BQ) to the catalytic system has a strong influence on the yield and, above all, on the molecular weight of polyketones. The zerovalent palladium complexes [Pd(N-N)(BQ)], which might be formed during the copolymerization process, have been synthesized and characterized. The crystal structure of [Pd(bipy)(BQ)] shows that benzoquinone acts as a mono-olefinic ligand to Pd. In the presence of protons, the Pd(0) complexes are readily oxidized to Pd(II) with the reduction of benzoquinone to hydroquinone. When [(N-N)H][X] is used as the source of protons, the resulting Pd(II) species is the precatalyst and can immediately re-enter the catalytic cycle.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. category: chiral-oxygen-ligands, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 538-58-9, in my other articles.
Reference£º
Synthesis and Crystal Structure of a Chiral?C3-Symmetric Oxygen Tripodal Ligand and Its Applications to Asymmetric Catalysis,
Chiral lanthanide(III) complexes of sulphur¨Cnitrogen¨Coxygen ligand derived from aminothiourea and sodium?D-camphor-¦Â-sulfonate