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

EFFECTS OF SOLVENTS ON THE ELECTRONIC AND MOLECULAR PROPERTIES OF 4-((2-METHYL-4-NITROPHENYL)IMINO)METHYL)PHENOL

Schiff bases are known to possess antiviral, antifungal, antibacterial, enzymatic and other significant biological properties. They also chelate metals to form complexes that have been used in industrial processes. Schiff bases are also important in modern energy applications due to their photometric and thermochemical properties. The basis of their applications depends on the molecular and electronic properties hence it is important to study how solvents perturb these properties. Therefore, this work is aimed at studying the electronic and molecular properties of a Schiff base. The effects of solvents on 4-(((2-methyl-4-nitrophenyl)imino)methyl)phenol was investigated both experimentally and theoretically. Experimentally, the UV-Visible spectrophotometer was used to obtain the absorption spectra of the compound in tetrahydrofuran, dichloromethane, propan-2-,ol, propan-1-ol, ethanol and methanol. Time-Dependent Density Functional Theory (TDDFT) and B3LYP with the 6-311++G(d,p) basis set was used to model and calculate the dipole moment, polarizability and excitation energies in vacuum, cyclohexane, methanol and ethanol using computational software. In the experimental studies, four bands were observed and designated I, II, III and IV in methanol and ethanol. However three bands were observed in propan-1-ol and propan-2-ol, and two bands in dichloromethane and tetrahydrofuran. A redshift was observed in Bands I and II while a blue shift was observed for Band III as solvent polarity increases. The intensity of the bands increased with increase in solvent polarity. The dipole moment and polarizability calculated using TDDFT increased with increasing solvent polarity. This may indicate the ease of charge separation and distortion of the electron cloud of the molecule as the polarity of solvent increases. On the basis of the observations of the transition energy and wavelength with solvent polarity, the compound can be classified to have both n→p* and p→p* transitions

Solvent effect and photo-physical properties of 2,3-diphenylcyclopropenone

The photo-physical properties of the strained ring 2,3-diphenylcyclopropenone (DPCP) containing donor–acceptor moieties in polar and non-polar solvent are reported. The transition dipole moment (Δμ), transition polarizability (Δα), oscillator strength (fij) and molar absorptivity (ε(ν¯)) of its different transition bands were determined using solvatochromic shifts theory. The determined Δα is positive, signifying the strong activity of this compound and its excited states being more polar than ground states. Its Δμ follows the trend observed for the fij and Δα. This conforms to the expectations that the more allowed a transition, the higher the probability that the transition dipole moments will be greater than zero. The transition dipole moment shows gradation of values, being smallest for the weak and forbidden transitions but increases considerably for the fully allowed transitions. The solvents perturbation allows the assignment of the transitions in this compound to be both n→π∗ and π→π∗ transitions