Mechanism-Guided Design of Robust Palladium Catalysts for Selective Aerobic Oxidation of Polyols.

The palladium complex [()Pd(μ-OAc)][OTf] ( = neocuproine) is a selective catalyst for the aerobic oxidation of vicinal polyols to α-hydroxyketones, but competitive oxidation of the ligand methyl groups limits the turnover number and necessitates high Pd loadings. Replacement of the neocuproine ligand with 2,2'-biquinoline ligands was investigated as a strategy to improve catalyst performance and explore the relationship between ligand structure and reactivity. Evaluation of [()Pd(μ-OAc)][OTf] ( = 2,2'-biquinoline) as a catalyst for aerobic alcohol oxidation revealed a threefold enhancement in turnover number relative to the neocuproine congener, but a much slower rate.

Effect of Redox Active Ligands on the Electrochemical Properties of Manganese Tricarbonyl Complexes.

The synthesis, structural characterization, and electrochemical behavior of the neutral Mn(azpy)(CO)(Br) 4 (azpy = 2-phenylazopyridine) complex is reported and compared with its structural analogue Mn(bipy)(CO)(Br) 1 (bipy = 2,2'-bipyridine). 4 exhibits reversible two-electron reduction at a mild potential (-0.93 V vs Fc in acetonitrile) in contrast to 1, which exhibits two sequential one-electron reductions at -1.

Control of clustering behavior in anionic cerium(iii) corrole complexes: from oligomers to monomers.

The first synthesis of anion capped cerium corrole complexes is reported. Unusual clustering of the lanthanide corrole units has been found and the degree of aggregation can be controlled by the choice of the capping ligand. A polymeric structure 1a, with the general formula [Cor-Ce(THF)-Cp-Na] (Cor = 5,15-bis(2,4,6-trimethylphenyl)-10-(4 methoxyphenyl)-corrole, THF = tetrahydrofuran), is formed using sodium cyclopentadienide (NaCp) and a dimeric structure 2a, with the general formula [Cor-Ce-Tp], is formed when potassium tris(pyrazolyl)borate (KTp) is used.