QSAR modeling of pyrazoline derivative as carbonic anhydrase inhibitors.

The efficacy of 34 pyrazoline derivatives as carbonic anhydrase inhibitors was studied in silico. The quantum descriptors were calculated by the DFT/B3LYP method using the 6-31G(d) basis; the dataset was randomly divided into training and testing. By altering the compounds in the sets, four models were created, and they were then used to determine the predicted pIC50 values for the six chemicals in the test set. According to the OECD guidelines for QSAR model validation and the Golbraikh and Tropsha's criteria for model approval, each created model was independently validated both internally and externally, along with YRandomization. Model 3 is chosen because it has higher R2, R2test, and Q2cv values (R2 = 0.79, R2test = 0.95, Q2cv = 0.64). Only one descriptor has a proportional influence on pIC50 activity, but the other four descriptors have an inverse influence on pIC50 because of the negative contribution coefficient. Given the descriptors of the model, we could propose new molecules with remarkable inhibitory activity.

A comprehensive assessment of carbon steel corrosion inhibition by 1,10-phenanthroline in the acidic environment: insights from experimental and computational studies.

1,10-Phenanthroline (PHN) is a nitrogen-containing heterocyclic organic compound that is widely used in a variety of applications, including chemosensors, biological studies, and pharmaceuticals, which promotes its use as an organic inhibitor to reduce corrosion of steel in acidic solution. In this regard, the inhibition ability of PHN was examined for carbon steel (C48) in a 1.0 M HCl environment by performing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), mass loss, and thermometric/kinetic. Additionally, scanning electron microscopy (SEM) was used to examine the surface morphology of C48 immersed in 1.0 M HCl protected with our inhibitor. According to the PDP tests, increasing the PHN concentration resulted in an improvement in corrosion inhibition efficiency. Besides, the maximum corrosion inhibition efficiency is about 90% at 328 K. Furthermore, the PDP assessments demonstrated that PHN functions as a mixed-type inhibitor. The adsorption analysis reveals that our title molecule mechanism is due to physical-chemical adsorption, as predicted by the Frumkin, Temkin, Freundlich, and Langmuir isotherms. The SEM technique exhibited that the corrosion barrier occurs due to the adsorption of the PHN compound through the metal/1.0 M HCl interface. In addition, the computational investigations based on a quantum calculation using density functional theory (DFT), reactivity (QTAIM, ELF, and LOL), and molecular-scale by Monte Carlo (MC) simulations confirmed the experimental results by providing further insight into the mode of adsorption of PHN on the metal surface, thus forming a protective film against corrosion on the C48 surface.

Mesoporous Silica Modified with 2-Phenylimidazo[1,2-a] pyridine-3-carbaldehyde as an Effective Adsorbent for Cu(II) from Aqueous Solutions: A Combined Experimental and Theoretical Study.

In this study, we will present an efficient and selective adsorbent for the removal of Cu(II) ions from aqueous solutions. The silica-based adsorbent is functionalized by 2-phenylimidazo[1,2-a] pyridine-3-carbaldehyde (SiN-imd-py) and the characterization was carried out by applying various techniques including FT-IR, SEM, TGA and elemental analysis. The SiN-imd-py adsorbent shows a good selectivity and high adsorption capacity towards Cu(II) and reached 100 mg/g at pH = 6 and T = 25 °C. This adsorption capacity is important compared to other similar adsorbents which are currently published. The adsorption mechanism, thermodynamics, reusability and the effect of different experimental conditions, such as contact time, pH and temperature, on the adsorption process, were also investigated. In addition, a theoretical study was carried out to understand the adsorption mechanism and the active sites of the adsorbent, as well as the stability of the complex formed and the nature of the bonds.

Kinetics, thermodynamics, equilibrium, surface modelling, and atomic absorption analysis of selective Cu(ii) removal from aqueous solutions and rivers water using silica-2-(pyridin-2-ylmethoxy)ethan-1-ol hybrid material.

The removal of heavy metals is attracting considerable attention due to their undesirable effects on the environment. In this investigation, a new adsorbent based on silica functionalized with pyridin-2-ylmethanol (SiPy) was successfully synthesized to yield to a hybrid material. FTIR, SEM, TGA, and specific surface area analysis were used to characterize the structure and morphology of the SiPy hybrid material. Various heavy metal ions such as Cu(ii), Zn(ii), Cd(ii), and Pb(ii) were selected to examine the adsorption efficiency of the newly prepared adsorbent, optimized at varying solution pH, contact time, concentration, and temperature. The adsorbent SiPy displayed good adsorption capacity of 90.25, 75.38, 55.23, and 35.12 mg g-1 for Cu(ii), Zn(ii), Cd(ii), and Pb(ii), respectively, at 25 min and pH = 6. The adsorption behaviors of metal ions onto the SiPy adsorbent fitted well with the pseudo-second-order kinetic mode and the isotherm was better described by the Langmuir isotherm. The thermodynamic studies disclose spontaneous and endothermic adsorption process. Furthermore, the SiPy adsorbent retained good selectivity and regeneration properties after five adsorption-desorption cycles of Cu(ii). A computational investigation of the adsorption mechanism indicates that the N-pyridine, O-hydroxyl, and ether O-atoms play a predominant role during the capture of Cu(ii), Zn(ii), Cd(ii), and Pb(ii). This study proposes the SiPy adsorbent as an attractive material for the selective removal of Cu(ii) from real river water and real industrial wastewater.

QTAIM and IRC studies for the evaluation of activation energy on the C=P, C=N and C=O Diels-Alder reaction.

In Diels-Alder reaction of 1,3-butadiene with hetero-dienophiles, the substitution of a carbon by a heteroatom as N, O and P on the dienophile decreases the activation energy, particularly for the phosphorus. All these reactions are concerted, proven by the DFT/B3LYP method using the cc-pVDZ basis. The intrinsic reaction coordinate (IRC) analysis confirms concerted reaction and the Quantum Theory of Atoms in Molecules (QTAIM) analysis shows that there are critical points BCP in the transition state structures with positive values for the interaction links.