Synthesis, characterization, molecular modeling and preliminary biochemical evaluation of new copper (II) mixed-ligand complexes

•Synthesis and characterization of new Cu(II) mixed-ligand complexes based on Schiff base and N-heterocyclic ligands.•Chemical descriptors evaluation based on DFT calculations.•In-vitro screening the inhibitory capacity of the synthesized compounds against the growth of pathogenic bacteria and fungi.•The complexes exhibited high catalytic phenoxazinone synthase-like activity.•Deriving SAR model between practical biological/catalytic activity and calculated chemical descriptors.