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This work reports on an inhibition and adsorption performance study of two quinazoline derivatives ((2-(2-chlorophenyl)-2,3-dihydroquinazolin-4(1H)-one) and (2-(2,4- dichlorophenyl)-2,3-dihydroquinazolin-4(1H)-one)) named ZB3 and ZB4, which were synthesized and examined using carbon nuclear magnetic resonance (13C NMR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. The assessment of the corrosion prevention of these two compounds for MS in 1.0 M HCl was performed employing potentiodynamic polarization (PDP) and (EIS) electronic impedance spectroscopy. The experiments performed showed that both derivatives operate well to prevent corrosion and their efficiencies exceed 85% at a concentration of 10-3. Moreover, it is discovered that the three chemicals' adsorption on the m-steel surface complies with Langmuir adsorption isotherm equation. The m-steel surface submerged in the corrosive solution was characterized by scanning electron spectroscopy (SEM) in conjunction with energy dispersive spectroscopy (EDS), spectroscopy using atomic force microscopy (AFM), X-Ray diffraction, and FTIR analysis. The findings showed that the examined inhibitors are well adsorbed, generating a barrier layer for the msteel's surface. DFT calculations and Monte Carlo (MC) simulation were used to directly correlate the electronic and adsorption properties, respectively, with the experimental corrosion inhibition efficiencies obtained for quinazoline and its 2 investigated derivatives. [ABSTRACT FROM AUTHOR]

In present work, two heterocyclic compounds namely 7-amino-2-(p-tolyl)-2H-thiazolo[3,2-a]pyrimidine-3,5-dione (ATTP) and 7-amino-2-(4-chlorophenyl)-2H-thiazolo [3,2-a]pyrimidine-3,5-dione (ACTP) were investigated for their inhibitory efficiencies against the corrosion of mild steel in HCl 1.0 M medium. Furthermore, the adsorption isotherm of these inhibitors was also studied, the results showing that the adsorption of inhibitors ATTP and ACTP on the surface of mild steel obey Langmuir isotherm. The negative values of ΔGads ° indicate the spontaneity of the adsorption process for both inhibitors. The calculated value of ΔGads ° indicates that the adsorption of ATTP on the surface of mild steel is mixed interaction (chemisorption and physisorption), while the calculated value of ΔGads ° of ACTP suggest the chemisorption adsorption. As well the Density Functional Theory (DFT) was used to study the relationship between the structure of the studied thiazolopyrimidines and their inhibitory efficiencies. The theoretical parameters obtained from DFT are in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The inhibiting power of two compounds of thiazolopyrimidine namely 7-amino-2-(p-tolyl)-2H-thiazolo[3,2-a] pyrimidine-3,5-dione (ATTP) and 7-amino-2-(4-chlorophenyl)-2H-thiazolo[3,2-a]pyrimidine-3,5-dione (ACTP) has been studied using electrochemical methods (potentiodynamic polarization and electrochemical impedance (EIS). It is observed that the inhibition efficiency increases with the increasing of the concentration for both studied inhibitors. Also, the maximum efficiency was obtained at 10-3M concentration. Potentiodynamic study indicates that ATTP acted as a mixed type with predominant cathodic, while ACTP acted as a cathodic inhibitor. The effect of the temperature was also studied in the temperature range 298 to 338 K. The results show that the inhibitory efficiency E (%) of ATTP and ACTP increases with the increasing of the temperature from 298 K to 318 K, then it decreases for a temperature higher than 318 K. [ABSTRACT FROM AUTHOR]

• PY-2Cl and PY-2Cl act as effective inhibitors for MS acidic corrosion. • The adsorption of PY-2Cl and PY-2Cl followed the Langmuir isotherm model. • Adsorption on the surface is analyzed by AFM, SEM/EDS, XRD, and FTIR techniques. • Theoretical data provide in-depth understanding of the experimental results. The present paper examines the adsorption of two novel heterocyclic compounds of the pyran derivatives, namely, 2-amino-4-(2-chlorophenyl)-5-oxo-4,5-dihydropyrano[3,2-c]chromene-3-carbonitrile (PY-2Cl) and 2-amino-4-(4-chlorophenyl)-5-oxo-4,5-dihydropyrano[3,2c]chromene-3-carbonitrile (PY-4Cl) against the corrosion of mild steel (MS) in molar hydrochloric acid (HCl) medium. The experimental investigation was carried out utilizing a series of techniques including Weight Loss (WL), Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP). Results showed that inhibition effectiveness of PY-2Cl and PY-4Cl increases with their concentration. Polarization results showed that PY-2Cl and PY-4Cl displayed mixed type behaviour. Inhibition efficiencies of PY-2Cl and PY-4Cl followed the order: 85.8% (PY-4Cl) < 91.2% (PY-2Cl).The adsorption process of PY-2Cl and PY-4Clonto MS surface follows Langmuir adsorption model. Surface characterization analysis utilizing Scanning Electron Microscopy (SEM) coupled with Energy dispersive X-ray analysis (EDS), Atomic Force Microscopy (AFM)and Infrared Spectroscopy (FT-IR) supported the existence of a barrier layer covering the MS. WL measurements were also tested utilizing inductively coupled spectroscopy (ICP) and UV–vis spectrometry (UV–vis). [ABSTRACT FROM AUTHOR]