The two synthesis of Schiff base SB (Indole-3-carboxalidene-1-phenylsemicarbazide) and organophosphorus Schiff base OPSB (Indole-3-carboxalidene diphenylphosphate-1-phenylsemicarbazide) have been prepared and characterized by elemental analyses, IR, 1H-NMR, 13C-NMR, UV–Vis and XRD. A series of complexes of the type [M(SB)2Cl2].2H2O and [M(OPSB)Cl.(H2O)2].Cl, where M = Cu(II), Ni(II) and Co(II) have been synthesized and the chemical structures of them were established by magnetic susceptibility, conductance measurements, elemental analyses, IR, UV–Vis. These results suggest that the metal complexes have octahedral geometry. X-ray powder diffraction analysis of ligands and SB complexes indicate that they are crystalline in nature and within nano range. The molecular docking of [Co(OPSB)Cl.(H2O)2].Cl is discussed using MOE software to understand the binding pattern of the investigated compound towards target proteins Bacillus subtilis (PDB ID: 2RHL), Staphylococcus aureus (PDB ID: 4URM), Escherichia coli (PDB ID: 4PRV), Pseudomonas aeruginosa (PDB ID: 4JVI). All compounds have been evaluated for their antimicrobial. The ligands and OPSB complexes showed high antioxidant activity.