Comparative Study of Halogen Substituted Isocyanatophosphine as an Adsorptive Inhibitor on Al (110) Crystal Surface, using Density Functional Theory.

To shield aluminium metals from the corrosion, a theoretical investigation on the ability to resist corrosion was carried out using the local density function Becke, 3-parameter, Lee–Yang–Parr (B3LYP) under limited spin polarization DNP+ basis in aqueous solution. The aim of the research was to obtain a stable geometry of the halogen substituted Isocyanatophosphine molecule, the local reactivity, and the global reactivity of the molecules as simulated on Al (110) surface. Some of the reactivities include the (ω+) electron accepting power which is in the order of 0.614<1.404<1.739<3.165 eV with DIP having highest accepting power and (ω-) electron donating power from 4.579< 6.015<6.445<7.891 eV and DFP having the highest accepting power. The energy gap (ΔEg) was in the order of 4.243<5.142<5.993<7.361eV; hence, DIP with 4.243eV is less stable and capable of been more reactive compare to DBP, DCP, and DFP. Fraction of electron transfer (ΔN) and Back-donation energy were in good agreement with each other in the order of 0.222<0.200<0.206<0.257% having DBP as the highest efficient molecule for the inhibition. The mode of interaction between the molecules and the surface of Al (110) was therefore established to be physisorption. The Binding energy of the molecules ranges between 15.708-22.298 kJmol-1. The Fukui function findings suggest the heteroatoms in a molecule nitrogen, oxygen, and halogen atoms been the focal point for the selectivity of electron donation and acceptance between the metal and the molecules. The molecules are tetragonal planar on the surface of the aluminium crystals.