Novel porphyrin derivatives as corrosion inhibitors for stainless steel 304 in acidic environment: synthesis, electrochemical and quantum calculation studies.

A Novel 5,10,15,20-tetra (thiophen-2-yl) porphyrin (P1) and 5,10,15,20-tetrakis (5-Bromothiophen-2-yl) porphyrin (P2) were successfully synthesized, and their chemical structures were proved based on its correct elemental analysis and spectral data (IR and H-NMR). These compounds were examined as corrosion inhibitors for stainless steel 304 (SS304) in 2 M HCl utilizing mass reduction (MR) and electrochemical tests at inhibitor concentration (1 × 10-21 × 10 M). The protection efficiency (IE %) was effectively enhanced with improving the concentration of investigated compounds and reached 92.