A bis(di-n-butyltin)-quinone derivative as a simultaneous chemo- and bioactive corrosion inhibitor

The bis(di-n-butyltin) derivative of 2,5-bis(2-hydroxyethylamino)-1,4- benzoquinone was synthesized and characterized by common spectroscopic techniques. In solution, discrete molecules with pentacoordinate tin atoms were observed, whereas the X-ray diffraction analysis of the solid-state structure revealed polymeric chains that were due to intermolecular Sn⋯O bonds. In vitro tests demonstrated that the tin compound displays bactericidal activity against a wide range of aerobic and anaerobic bacteria. Acute toxicity tests indicated that the di-n-butyltin compound has a relatively low toxicity level. The corrosion inhibition efficiency of the ligand and the tin compound were evaluated by polarization scans of mild steel samples that had been exposed to a sour brine environment. The tin-quinone compound showed good inhibition efficiency (about 75 %) at relatively low concentrations (25-50 ppm) and at different testing times (0.25-20 h).