Spectroscopic studies of interaction of safranine T with ionic surfactants

•Safranine T is a photosensitive cationic phenazine dye.•Anionic surfactant at low concentration forms complex with dye molecule.•In SDBS and SDMA media, dye forms isosbestic point.•212 does not form charge transfer complex, but it acts as a quencher.•Above cmc, anisotropy value remains constant as the restriction is saturated.

Dye–surfactant interaction has great importance in scientific fields. The dye–surfactant interactions are generally complex processes. Safranine T is a photosensitive cationic dye whose ground and excited state spectra are affected by the surfactant. Anionic surfactant at low concentration forms complex with dye molecule. In anionic surfactant media, dye also forms dimer. After cmc (critical micelle concentration), charge transfer complex is formed between the anionic surfactant micelle and safranine T molecule. SDBS and SDMA form isosbestic point. 212 does not form charge transfer complex but it acts as a quencher. In case of SDS, maximum decrease in the value of absorbance of dye is observed compared to other surfactants and in case of SDMA, minimum decrease of fluorescence intensity is noticed. Cationic surfactants have little interaction with this cationic dye. CTAB has no interaction.

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