Experimental and Theoretical Studies on the Corrosion Inhibition of Brass in Hydrochloric Acid by N-(4-((4-Benzhydryl Piperazin-1-yl) Methyl Carbamoyl) Phenyl) Furan-2-Carboxamide

The corrosion inhibition effect of N-(4-((4-Benzhydryl piperazin-1-yl) methyl Carbamoyl) Phenyl) Furan-2-Carboxamide (BFC) on brass in 1M HCl has been investigated using weight loss method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The result reveals that BFC acts as a mixed type corrosion inhibitor with more pronounced effect on anodic domain and the inhibition efficiency of BFC increases with increase in temperature ranges from 30°C to 60°C. AC impedance implies thatRctvalue of BFC increases with increase in concentration. CV indicates that the addition of inhibitor controls the oxidation of the copper on the brass metal. The structural confirmation of BFC was carried out by the spectral studies like FT-IR,1H NMR,13C NMR, and the molecular weight was confirmed by LC-MS. Surface characterization of brass with BFC was analysed using scanning electron microscope (SEM). Quantum chemical parameter was used to calculate the electronic properties of BFC in order to confirm the correlation between the inhibitor effect and molecular structure of BFC. BFC has more negative charge on nitrogen and oxygen atom, which facilitates the adsorption of BFC on the surface of brass.

QSPR Models for the Physicochemical Properties of Polychlorinated Naphthalene Congeners

Based on quantitative structureproperty relationship (QSPR) of organic compounds, geometrical optimization and quantum chemical parameter calculations have been performed at the B3LYP/6-31G* level of theory for 75 polychlorinated naphthalenes (PCNs). A number of statistically-based parameters have been obtained. Relationship between the physicochemical properties of polychlorinated naphthalene compounds (n-octanol/air partition coefficient, sub-cooled liquid vapor pressure, water solubility) and the structural descriptors have been established by multiple linear regression (MLR) method. The results show that the molecular volume (Vmc), dipolar moment (μ), and the energy of lowest unoccupied molecular orbital (ELUMO), together with the quantity derived from electrostatic potential () can be well used to express the quantitative structure-property relationships of polychlorinated naphthalene compounds. The models constructed have good robustness and high predictive capability.