Papiya Jana2, C. Sundar Raj1 and Asok K. Jana1*
1Department of Chemistry, Kanchi Mamunivar Centre for Post-Graduate Studies, Pondicherry-605 008, India
2Department of Chemistry, Sri Manakula Vinayagar Engineering College, Pondicherry-605107, India
A B S T R A C T
The dye, Pinacyanol chloride (PCYN) exhibits two absorption maxima i.e., α and β – bands at 600 and 550 nm, respectively. The spectrophotometric study of pinacyanol chloride with three different types of surfactants such as CTAB (cationic), SLS (anionic) and Triton X – 100, Tween 20, 40, and 80 (nonionic) in aqueous media show that PCYN forms a 1:1 molecular complex with Triton X-100, Tweens and SLS corresponding α and β -bands of dye. Such type of interaction is absent in between PCYN and CTAB. The thermodynamic and spectrophotometric properties of these complexes suggest that PCYN forms strong charge-transfer (CT) complexes with Triton X-100 and Tweens at α band of dye compared to its β – band, whereas the interaction of PCYN with SLS is columbic in nature. The photo galvanic and photo conductometric studies also supported the above interaction. In addition to this, the electron donating ability of the nonionic surfactants towards dye, role of surface in CT interaction, the site of interaction and also instability of CT complexes have been pointed out.
Keywords: PCYN, Tweens, CT complex, Instability constant, Photo galvanic effect