Résumé:
The capacity of a series of derivatives of the thiadiazole molecule 2-amino-1,3,4-thiadiazole (ATD), including 5-amino-1,3,4-thiadiazole-2-thiol (ATDT), 2-amino-5-ethyl-1,3,4-thiadiazole (AETD) and 2-amino-5-tert-butyl-1,3,4-thiadiazole (ATBTD), to inhibit the corrosion of an iron substrate in 1 M HCl was investigated. An extensive theoretical study was carried out to examine adsorption modes and electronic structures, and to identify and quantify the nature of interactions at the inhibitor/substrate interface, using density functional theory (DFT/B3LYP) calculations based on Grimme's method for DFT-D correction, in combination with a dual digital plus polarisation (DNP) basis set, and Monte Carlo simulations based on the simulated annealing algorithm via automated temperature control using the DMol3 and Adsorption Locator modules implemented in Material studio 17 software. 0. The effect of the solvent was represented by the implicit solvation model COSMO. The inhibitors studied show spontaneous and favorable adsorption, but the expected order of effectiveness is: ATDT > ATBTD > AETD > ATD. ATDT was the most effective of the inhibitors studied.
