Synthesis, characterization, anti-corrosion behavior and theoretical study of the new organic dye: 3-oxo-3H-spiro[isobenzofuran-1,9´-xanthene]-3´,6´-diyl bis(3-methyl-benzenesulfonate)

The present work covers the recent synthetic of 3-oxo-3H-spiro[isobenzofuran-1,9´-xanthene]-3´,6´-diyl bis (3-methylbenzenesulfonate) in high yield attain 91% through reaction between fluorescein and 4-methylbenzenesulfonyl chloride for 8 hours under different operating conditions.We have developed an environmentally friendly compound, mild condition protocol and convenient procedure for the preparation of this xanthene derivative.The structure of the new organic dye was determined by spectroscopic methods such as: 1 H NMR, 13 C NMR, infrared and MS data.This reaction has been studied also theoretically using Gaussian 09 software based on the DFT method at B3LYP/6-31G(d,p), in order to explain the possibility of these reaction through the quantum chemical parameters.The results obtained theoretically are in good correlation with those obtained experimentally.The inhibition effect of 3-oxo-3Hspiro[isobenzofuran-1,9´-xanthene]-3´,6´-diyl bis(3-methyl-benzenesulfonate (NAR1) on the corrosion of mild steel in molar hydrochloric acid solution.The experimental part was performed by studying the stability of the synthetic product in the corrosive medium and the inhibition behavior was investigated using absorbance difference measurements; the result indicates that NAR1 is a good inhibitor in acidic medium at low concentration at 1 ppm, the percentage of inhibition efficiency achieves 93%.The surface analysis of mild steel was investigated using scanning electron microscopy (SEM) and Energy dispersive X-ray (EDX) methods and show the adsorption behavior of inhibitor on the surface of mild steel.