New strategy of synthesis, characterization, theoretical study and inhibition effect on mild steel corrosion in acidic solution
<p>We report two new different synthesis strategies of an eco-friendly organic dye 3-oxo-3H-spiro[isobenzofuran-1,9'-xanthene]-3',6'-diyl diacetate. These methods were based on the reaction of fluorescein with acetic anhydride under different experimental conditions. The synthesized heterocyclic system obtained with excellent yield was characterized by FT-IR, <sup>1</sup>H N.M.R., <sup>13</sup>C N.M.R., and mass spectrometry. This reaction has also been studied theoretically using Gaussian 09 based on the DFT method at B3LYP/6-31G (d, p). The results obtained are in good correlation with those obtained experimentally. The inhibition behavior of the synthetic product has been studied using absorbance difference measurement, the percentage of inhibition efficiency attains 90% at 10<sup>-4</sup>M of NAR3 inhibitor. The surface analysis of mild steel was investigated using scanning electron microscopy (S.E.M.) and Energy Dispersive X-ray (E.D.X.) methods and show the adsorption behavior of inhibitor on the surface of mild steel.</p>