A Comparative Analysis of the Global Electrophilicity Power of Some Cationic Dyes. Understanding Selective Removal Dyes From Mixture Solution

Some bibliographic findings of dyes' adsorption from a mixture state suggest that certain dyes are more likely to be adsorbed first on the adsorbent surface than others, and therefore attracted strongly to the adsorbent surface. To explain the phenomenon, DFT calculations are applied. In this fact, the global electrophilicity index ω of some cationic dyes has been evaluated. The results show that, for studied electrophilic dyes, the molecule with the greatest global electrophilicity power is favored to be adsorbed on the surface's anionic sites. In addition, local electrophilic Parr and Fukui functions were introduced to characterize the most reactive adsorption sites properly and indicate successfully the same adsorption centers. The success of DFT calculations in explaining and predicting the selective dye was assessed.