The Corrosion Inhibition Effect of Pyrrole Derivatives on Carbon Steel in 1.0 M HCl

The inhibition effect of new pyrrole derivatives, namely, 13-((4-aminophenyl) sulfonyl)-10,11-dihydro-9H-9,10-[3,4] epipyrrolo anthracene-12,14(13H, 15H)-dione (1), anthracen-9(10H)-ylidenehydrazine( 2),(11S, 15R)-13-(anthracen-9(10)-ylideneamino) 10,11-dihydro-9H-9,10 [3,4] epipyrroloanthracene-12,14-(13H, 15H)-dione (3), 1,6-bis-(N -hexachloro-5-norbornene-2,3-dicarboximidyl) hexane (4) and N-Phenylsulfonyloxy-hexachloro-5-norbornene-2,3-dicarboximide (5), against the corrosion of carbon steel in 1.0 M HCl solution has been systematically studied by electrochemical measurements (potentiodynamic polarization measurements -impedance spectroscopy-electrochemical frequency modulation). The results of Potentiodynamic polarization indicate that all pyrrole derivatives are Mixed type inhibitors. Among the studied compounds, exhibited the best inhibition activity of 82.8% at 21x10(-6)M from compound (1). The chemical structure of the synthesized compounds was established by proton and carbon thirteen nuclear magnetic resonance (H-1-NMR),(C-13-NMR), Fourier transform infrared (FTIR) and mass spectroscopy. Solution analysis (UV-visible spectrophotometric method-Fourier transform infrared [FTIR]) support the above inferences.