Molecular spectroscopic kinetic and computational studies on charge transfer complexes of dibenzothiophene azomethine with nitrobenzene as π-acceptors and its antibacterial effect

Promising charge transfer (CT) complexes were prepared to be used as: solid conducting electrolytes for batteries voltaic cells, biosensors, biochips, diagnostic applications and the electronic devices. Charge transfer (CT) complexes generated between electron Schiff bases donor of Aryl 2-azomethine dibenzothiophene-Schiff base, 1,3-dinitrobenzene ( A 1), 2,4-dinitrophenol ( A 2) and picric acid ( A 3) as-acceptors have been studied using spectroscopic kinetic investigations. The reactions of the donor and the acceptor compounds were followed at different temperatures (20, 30, 40 and 50 °C) and in the range of time between 0 and 55 min. The rate of formation of the product ( k ) and the molar extinction coefficient ( ε ) has been calculated and discussed. The activation energy ( E a ) has been calculated from the first-order kinetic equation. The thermal dehydration and decomposition of these complexes were studied kinetically using the integral method applying the Coats–Redfern, Ozawa and composite methods. These donor–acceptor charge transfer complexes have a promising antimicrobial activity comparable to the corresponding schiff base compound. TGA-DTA and DSC studies were also carried out to check the stability of CT complex, and activation energy ( E a ) has been calculated. These donor–acceptor charge transfer complexes and the attributed of N, O and S atoms have a promising antimicrobial activity that suggested the applications of this class of compounds in pharmaceutical and medical applications. The antibacterial and antifungal activities of the synthesized charge transfer complexes were screened against and fungi ( Candida ) bacterial species ( Escherichia coli and Staphylococcus aureus ). The activity data show that the CT complexes have a promising biological activity comparable to the Schiff base compound against bacterial and fungal species. These CT complexes comparable to the corresponding schiff base compound have semiconducting and piezoelectric properties electronic conductivity. The piezoelectric polarization is induced due to the reorientation of the polar groups and its dipoles. The phase transition on heating the complexes reflects the dielectric nature due to the defect and the transport properties.