Synthesis, characterization and corrosion inhibition efficiency of 2-(6-methylpyridin-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline on mild steel in sulphuric acid

AbstractPhenanthroline derivative, 2-(6-methylpyridin-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline (MIP) was synthesized and characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, and single crystal X-ray diffraction study. MIP was evaluated as corrosion inhibitor for mild steel in 0.5M H2SO4 solution using gravimetric and UV–Visible spectrophotometric methods at 303–333K. Results obtained show that MIP acts as inhibitor for mild steel in H2SO4 solution. The inhibition efficiency was found to increase with increase in MIP concentration but decreased with temperature. Activation parameters and Gibbs free energy for the adsorption process using statistical physics were calculated and discussed. The UV–Visible absorption spectra of the solution containing the inhibitor after the immersion of mild steel specimen indicate the formation of a MIP-Fe complex

Can Taxpayers Stand Discrimination?: Lack of Standing and the Religious Freedom Restoration Act Permits the Executive Branch to Fund Discrimination Within Religious Organizations

The Density Functional Theory (DFT) and ab initio (HF and MP2) calculations were performed on the quinoline molecule (QL) and its derivatives, namely quinaldine (QLD) and quinaldic acid (QLDA) to investigate their possible role as corrosion inhibitors for mild steel in acidic medium. Calculations were done for non-protonated and protonated forms in vacuo and in water. Some quantum chemical parameters were calculated and discussed in order to provide insight into the reactivity and selectivity of the molecules. The performance of the different calculation methods were also compared with available experimental data. The results show that DFT/B3LYP basis set is adequate in describing the geometry and quantum chemical parameters of the studied systems. Both experimental and theoretical results established that QLDA has the highest inhibition efficiency. A comparison in the trends of the quantum chemical parameters in water solution and in vacuo shows minimal influence of the solvent effects

Surface protection of mild steel using benzimidazole derivatives: experimental and theoretical approach

<div><p>Interaction of organic molecules with the surface of metals plays important role in many applications. In particular, surface protective applications need much explanation from both experimental and theoretical point of view. Herein, we have investigated the surface adsorption characteristics and corrosion inhibition behavior of two new benzimidazole derivatives namely 2-(2-Bromophenyl)-1H-benzimidazole (BPBA) and 2-(2-Bromophenyl)-1-methyl-1H-benzimidazole (BPMA) on mild steel in 0.5 M HCl solution using experimental and theoretical approach. Electrochemical and weight loss experiments were used to elucidate the corrosion inhibition potentials of BPBA and BPMA. Attenuated total reflectance-Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, and X-ray photoelectron spectroscopy measurements were performed to confirm the adsorption of BPBA and BPMA on mild steel surface. Computer simulations were further employed to provide additional insights into the mechanism of interaction between the inhibitors and the steel surface. All the results confirmed that BPMA is a better corrosion inhibitor for mild steel than BPBA in 0.5 M HCl. This new inhibitors could find application industrially during processes such as oil well acidizing for steel protection against corrosion.</p></div

Quantum chemical studies on the corrosion inhibition of mild steel by some triazoles and benzimidazole derivatives in acidic medium

Quantum chemical calculations using the Density Functional Theory (DFT) method at three different basis sets, namely, 6-31(d,p), 6-31+(d,p) and 6-311G(d,p) were performed on selected triazole and benzimidazole derivatives, namely 2-aminobenzimidazole (ABI), 1,3-benzothiazole (BTH), benzotriazole (BTA), 2-methylbenzimidazole (MBI), 2-(2-pyridyl)benzimidazole (PBI), 2-(amino methyl)benzimidazole (AMBI), 5-amino-3-mercapto-1,2,4-triazole (5AMTZ), 2-hydroxybenzimidazole (HBI), benzimidazole (BI) and 5-amino-1,2,4-triazole (5ATZ), to determine their reactive centres which might interact with the metal surface on the adsorption of the these compounds onto the metal surface. The results show that the adsorption of the inhibitor onto the metal surface would preferentially be through the benzene ring that is fused to the heterocyclic ring and through the heteroatoms of the heterocyclic ring. The study on the protonated species of the studied compounds show that they have the least tendency to chemically adsorb onto the metal surface and might preferentially adsorb physically. The quantitative structure activity relationship approach indicates that three to four quantum chemical parameters are needed to effect a reasonable correlation between experimentally determined and theroetically estimated inhibition efficiencies. © 2012 by ESG