The use of quantum chemical methods in corrosion inhibitor studies

A computational study of two hexitol borates as corrosion inhibitors for steel

“…Commonly, the atom which contributes more to the HOMO should have the stronger ability for detaching electrons, whereas, the atom which occupies the main component of the lowest unoccupied molecular orbital (LUMO) should be easier to gain electrons. Reportedly, excellent corrosion inhibitors are usually those organic compounds that not only offer electrons to the unoccupied orbital of the metal, but also accept free electrons from the metal [9]. A high value of the HOMO energy corresponds to copious donation of electrons to congruent molecules with low energy, empty molecular orbitals.…”

“…Although much has been learned from this experimental study, an explanation from a theoretical perspective for the justification of the inhibition effects of these molecules needs to be held alongside an explicit conclusion about the underlying inhibition mechanism. Prompted by the successful application of theoretical calculations in corrosion inhibitor research [9], this paper is a further contribution to gain a better understanding of the inhibition effects of rutin and artesunate through a density functional theory (DFT) based approach. This approach allows an accurate calculation of a number of physical and chemical properties, some of which can either be compared directly to experiment or are complimentary to it [10][11][12][13].…”

Spectral investigation of the Piperazine Dithiosemicarbazone Derivatives as inhibitor on High Carbon Steel in HCl media

“…Fig 2 showed the Nyquist plots of the HCS in the absence and presence of the inhibitor in the 1M HCl medium. The impedance curves reveal depressed semicircle capacitive loop at the higher frequency, small inductive loop at low frequency [15][16][17]. The capacitive loop originates from the adsorption on the reaction surface and charges transfer resistance (R ct ) [18][19][20][21].…”

A Study into the Corrosion Inhibition of Carbon Steel in Acidic Medium Using Eco-Friendly Compounds

“…Additionally, the Mulliken atomic distribution of hetero-atomic Table 4 describe the possible active sites in the inhibitor molecule that bear a higher negative charge to participate in electrostatic attraction 95,98 . In other words, as mentioned in elsewhere 12,99 the values are very instructive and a good indicator to interpret the active site for the organic compounds when it interacts with a metal surface. The localization of the high negative charge on hetero-atoms in drug inhibitor molecules is related to the susceptibility towards adsorption on the surface of the electrode through the donor-acceptor reactions 37,89,100,101 .…”

“…The development of new inhibitors from natural sources is both important and desirable. There are similarities to the drug discovery process, as many chemical compounds which are used as medicines may be perfect applicants to substitute as conventional toxic compounds as inhibitors [11,12].The importance of the use of many drugs has led to the growth of corrosion inhibitors [7,13]. There are many previous reports which have examined drugs such as melatonin 7 , valorization 13 , antihypertensive 14 ,Ibuprofen salicylate 15 , benzyl penicillin 16 ,amlodipine besylate 17 ,streptomycin 18 , ketosulfone 19 , pheniramine 20 , imidazole-based antifungal 21 , rhodanine azosulpha 22 , cefalexin 23 , and ceftriaxone 24 , as corrosion inhibitors for iron and its alloys in several kind of acidic solutions.…”