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 Ni II –Mn II complexes of a N 2 O 2 donor unsymmetrical ligand: synthesis, structures, magnetic properties and catalytic oxidase activities”, Dalton Trans. , 2018, 47 ,