POTENTIAL ELECTROSTATIC AND LOCAL FUKUI FUNCTIONS IN THE STUDY SOLVATION OF A DYE MIXTURE

Background: Synthetic dyes are of a great importance in the textile and food industry since they allow to satisfy the trade requirements of consumers in the final products. Indigo Blue dye (IB) is widely used for dyeing cloth and shows solvation difficulties that are overcome only by a reduction reaction, which can change this behavior as a result of intermolecular interactions.

Methods: In the present study it was found that the IB undergoes solvation in an aqueous medium in the presence of red dye 40, (R40). All molecules were optimized using the theory of density functional model with B3LYP and 6-31G basis sets that are implemented in the computer program Gaussian 09. The calculation of the electrostatic potential of both dyes was carried out by software package TopMoD.

Results: To explain this fact, computational analysis was performed using the condensed Fukui function and the electrostatic potential of the selected molecules, which showed the interaction between the two dyes mediated by hydrophobic attractions of its aromatic rings.

Conclusions: This study allowed to support the molecular interaction of the IB and R40 dyes, which was mediated mainly for hydrophobic interactions between the aromatic rings.