Comment on "Mixed azido/phenoxido bridged trinuclear Cu(ii) complexes of Mannich bases: synthesis, structures, magnetic properties and catalytic oxidase activities", Dalton Trans., 2018, 47, 9385-9399 and "Tri- and hexa-nuclear NiII-MnII complexes of a N2O2 donor unsymmetrical ligand: synthesis, structures, magnetic properties and catalytic oxidase activities", Dalton Trans., 2018, 47, 13957-13971.

This letter comments on two examples of numerical results of kinetic parameters which are inconsistent with the experimental data given in the same articles. Since this seems to be a trend in inorganic chemistry articles dealing with the catalytic oxidation of 3,5 di tert- butylcatechol and ortho-aminophenol, we call the attention of editors, reviewers and readers about grossly overestimated catalytic parameters in the literature.