Steric and electronic effects of ligand variation on cobalt dioxygen catalysts

Abstract

We report herein the observation that electronic and steric factors of cobalt dioxygen complexes with systematically derivatized pentadentate Schiff-base ligands affect their ability to catalyze the oxidation of substituted phenols and alter the rate of catalyst decomposition. The electronic and steric factors can be separated sufficiently to indicate that the activity of the cobalt dioxygen catalyst roughly parallels the trends in basicity of the bound 02 suggested by EPR cobalt hyperfine coupling constants of the adducts and predicted from the electronic effects of substituents.

Catalytic applications of CuII-containing MOFs based on N-heterocyclic ligand in the oxidative coupling of 2,6-dimethylphenol

“…As expected, both complexes can catalyze efficiently this polymerization with high activities and selectivities, viz., the selectivity to PPE is almost 90% for the two complexes, and the conversion of DMP is 85% for 1 and 90% for 2, which can match the reported well-known catalysts [32][33][34][35][36]. The origin of the interesting reactivities of complexes is thus discussed as well.…”

“…0 -bis[(N-methyl-2-pyridyl)ethylamino]-2-fluoro-m-xylene)give the excellent conversions of DMP of 100%, 91% and 96%, but with only moderate selectivities of 43%, 50.6% and 27.1% toward PPE in 24 h, 5 h and 6 h, respectively (entries 1, 2 and 7)[33,34,36]. In the case of [Cu(tmeda)] AE Cl 2…”

Effect of the structure of copper(II) complexes, adsorbed on the surface of SiO2, on their catalytic activity in ozone decomposition

“…In this case, the maximum number of catalytic cycles is provided by the most active complex Cu(L3) 2 /Si. The result obtained is not inconsistent with the data in [14], according to which the active complexes of 3d metals with Schiff's bases provide a greater The substantial effect of the nature of the ligands on the catalytic activity of anchored copper(II) complexes has been established. Thus the activity and number of catalytic cycles in the case of CuCl 2 /SiO 2 complexes is higher than for Cu(NO 3 ) 2 /SiO 2 .…”

The interaction between sulfathiazole and cobalt(II): potentiometric studies

“…In this sense, the Co(II) complexes with N donor ligands are known for their ability to bind dioxygen more or less reversibly and therefore frequently studied for their importance in industrial processes and as model compounds [16][17][18] .…”