Investigation of the Inhibition effect of newly synthesized pyrazoline derivative on mild steel in Hydrochloric acid medium by Experimental and Theoretical approach

•Synthesized pyrazoline derivative 5-[5-(4-bromophenyl)1-1(pyridine-2-yl)-4-5-dihydro-14-pyrazol-3-yl]-2-methoxy pyridine (BPPM) and characterized by IR and NMR spectroscopy.•The electrochemical studies were carried out using electrochemical impedance spectroscopy and potentiodynamic polarization studies.•Surface characteristics of mild steel sample was performed with the use of scanning electron microscopy (SEM) and Energy Dispersive X-ray analysis (EDX).•The quantum chemical calculations were performed with the help of the DFT/B3LYP level using Gaussian 16 software for the neutral and protonated form of BPPM.•The UV-Visible spectroscopic study has been employed to confirm the formation of metal-inhibitor complex.