Investigating the photosensitized reaction of methylene blue with toluidines: A spectroscopic and kinetic analysis

Abstract

The photosensitized reaction of isomeric Toluidines was investigated in an alkaline medium under visible light, utilizing methylene blue (MB) as a photosensitizer. The reaction starts with an exciplex forming between nitrogen and the dye, and when it is exposed for a while, it breaks apart, creating photoproducts. UV-visible spec- troscopy was used to study the reaction. To see how oxygen affects it, the reaction was conducted without oxygen, and methanol was added to check if it removes harmful particles. Additionally, factors like pH, the amount of dye, the amount of the substance under study, and the brightness of the light were examined for their impact on the reaction rate. The efficiency of the reaction in using light was calculated. Finally, a possible explanation of how the reaction works was formulated in the proposed mechanism.