Laboratoire des Substances Naturelles & Synthèse et Dynamique Moléculaire, Faculté des Sciences et Techniques, Université Moulay Ismail, Errachidia, Morocco
Menthone, is a monoterpene ketone, occurs in nature and widely present in high concentration in mentha species essential oils. Also, it has become the key to the synthesis of many heterocyclic compounds exhibiting various kinds of biological activity. The objective of the present work is to synthesize new menthone derivative compounds such as menthopyrazole (HPM) and 1-phenylmenthopyrazole (PMP) by condensation of hydroxymethylenementhone with hydrazine and phenylhydrazine, respectively. The structures of these compounds were characterized by FT-IR, 1H NMR and 13C NMR spectra.
The corrosion-inhibition efficiency of Pulegone and Pulegone oxide, and the corresponding protonated molecules have been studied computationally using density functional theory. The iron-inhibitor-iron complexes were constructed by interaction the heteroatom to the iron surface modeled by one iron atom. Relations between molecular properties and corrosion-inhibition efficiency were determined by using linear regression and quantitative structure–activity relationship (QSAR). The QSAR analysis yielded significant correlations between the corrosion-inhibition activity of the studied molecules with molecular properties such as the highest occupied molecular orbital, the lowest unoccupied molecular orbital, dipole moments, and the total atomic charges. Fukui indexes were also calculated for assessing correlation between them and experimental corrosion-inhibition efficiencies. The efficiency order of two inhibitors is found to be Pulegone >Pulegone oxide which accords with experimental results.