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Quenching of the triplet state of safranine-O by aliphatic amines in AOT reverse micelles studied by transient absorption spectroscopy

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The photophysics of Safranine-O (3,6-diamino-2,7-dimethyl-5 phenyl phenazinium chloride) (SfH+ Cl) was investigated in reverse micelles (RMs) of AOT (sodium bis(2-ethylhexyl)sulfosuccinate) with special emphasis on the triplet state processes. The triplet is formed in its monoprotonated form, independently of the pH of the water used to prepare the RMs. While the intersystem crossing quantum yields in RMs are similar to those in organic solvents, the triplet lifetime is much longer. Since the pH in the water pool of AOT RMs is close to 5 and the triplet state of the dye is subjected to proton quenching, the long lifetime indicates that the dye resides in a region where it cannot be reached by protons during its lifetime. All the measurements indicate that the dye is localized in the interface, sensing a medium of micropolarity similar to EtOH : water (3 : 1) mixtures. The quenching by aliphatic amines was also investigated. While the quenching by the hydrophobic tributylamine is similar to that in methanol, the hydro-soluble triethanolamine is one order of magnitude more effective in RMs than in homogeneous solution. In the latter case the quenching process is interpreted by a very fast intramicellar quenching, the overall kinetics being controlled by the exchange of amine molecules between RMs. Semireduced dye is formed in the quenching process in RMs in the di-protonated state with a comparable quantum yield to the monoprotonated state formed in homogeneous solvents. The results point to the advantage of the reverse micellar system for the generation of active radicals for the initiation of vinyl polymerization, since a much lower concentration of amine can be employed with similar quantum yields.

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References

  1. P. L. Liusi and B. E. Straubs, (ed.), Reverse Micelles, Plenum Press, New York, 1984

    Google Scholar 

  2. T. K. De, A. Maitra, Solution behaviour of Aerosol OT in non-polar solvents, Adv. Colloid Interface Sci., 1995, 59, 95–193

    Article  CAS  Google Scholar 

  3. A. Mallick, P. Purkayastha, N. Chattopadhyay, Photoprocesses of excited molecules in confined liquid environments: An overview, J. Photochem. Photobiol., C, 2007, 8, 109–127.

    Article  CAS  Google Scholar 

  4. W. D. Van Horn, M. E. Ogilvie, P. F. Flynn, Reverse Micelle Encapsulation as a Model for Intracellular Crowding, J. Am. Chem. Soc., 2009, 131, 8030–8039.

    Article  Google Scholar 

  5. M. Wong, J. K. Thomas, T. Nowak, Structure and state of water in reversed micelles, J. Am. Chem. Soc., 1977, 99, 4730–4736

    Article  CAS  Google Scholar 

  6. B. Baruah, J. M. Roden, M. Sedgwick, N. M. Correa, D. C. Crans, N. E. Levinger, When Is Water Not Water? Exploring Water Confined in Large Reverse Micelles Using a Highly Charged Inorganic Molecular Probe, J. Am. Chem. Soc., 2006, 128, 12758–12765

    Article  CAS  Google Scholar 

  7. B. Baruah, L. A. Swafford, D. C. Crans, N. E. Levinger, Do Probe Molecules Influence Water in Confinement?, J. Phys. Chem. B, 2008, 112, 10158–10164.

    Article  CAS  Google Scholar 

  8. M. Zulauf, H. F. Eicke, Inverted micelles and microemulsions in the ternary system water/aerosol-OT/isooctane as studied by photon correlation spectroscopy, J. Phys. Chem., 1979, 83, 480–486

    Article  CAS  Google Scholar 

  9. E. Keh, B. Veleur, Investigation of water-containing inverted micelles by fluorescence polarization. Determination of size and internal fluidity, J. Colloid Interface Sci., 1981, 79, 465–478

    Article  CAS  Google Scholar 

  10. E. Bandez, E. Monnier, B. Valeur, Dynamics of excited-state reactions in reversed micelles. 2. Proton transfer involving various fluorescent probes according to their sites of solubilization, J. Phys. Chem., 1985, 89, 5031–5036

    Article  Google Scholar 

  11. J. Peyrelasse, C. Boned, Study of the structure of water/Aerosol OT/dodecane systems by time domain dielectric spectroscopy, J. Phys. Chem., 1985, 89, 370

    Article  CAS  Google Scholar 

  12. M. P. Pileni, B. Hickel, C. Ferradini, J. Pucheault, Hdyrated electron in reverse micelles, Chem. Phys. Lett., 1982, 92, 308–312.

    Article  CAS  Google Scholar 

  13. I. Capek, Fate of excited probes in micellar systems, Adv. Colloid Interface Sci., 2002, 97, 91–149.

    Article  CAS  Google Scholar 

  14. S. C. Bhattacharya, H. Das, S. P. Moulik, Quenching of the fluorescence of safranine T by inorganic ions in aqueous and non-ionic micellar media, J. Photochem. Photobiol., A, 1994, 84, 39–44

    Article  CAS  Google Scholar 

  15. P. Ray, S. C. Bhattacharya, S. P. Moulik, Spectroscopic studies of the interaction of the dye safranine T with Brij micelles in aqueous medium, J. Photochem. Photobiol., A, 1997, 108, 267–272

    Article  CAS  Google Scholar 

  16. H. W. Gao, Q.-S. Ye, W.-G. Liu, Langmuir aggregation of nile blue and safranine T on sodium dodecylbenzenesulfonate surface and its application to quantitative determination of anionic detergent, Anal. Sci., 2002, 18, 455–459.

    Article  CAS  Google Scholar 

  17. Maged A. El-Kemary, Rehab A. Khedr, Safaa El-Din, H. Etaiw, Fluorescence decay of singlet excited-state of safranine T and its interaction with ground-state of pyridinthiones in micelles and homogeneous media, Spectrochim. Acta, Part A, 2002, 58, 3011–3019.

    Article  Google Scholar 

  18. G. Zhang, Y. Pang, S. Shuang, C. Dong, M. M. F. Choi, D. Liu, Spectroscopic studies on the interaction of Safranine T with DNA in β-cyclodextrin and carboxymethyl-β-cyclodextrin, J. Photochem. Photobiol., A, 2005, 169, 153–158.

    Article  CAS  Google Scholar 

  19. D. Bose, D. Sarkar, A. Girigoswami, A. Mahata, D. Ghosh, N. Chattopadhyay, Photophysics and rotational relaxation dynamics of cationic phenazinium dyes in anionic reverse micelles: Effect of methyl substitution, J. Chem. Phys., 2009, 131, 114707.

    Article  Google Scholar 

  20. S. Pramanik, S. C. Bhattacharya, T. Imae, Fluorescence quenching of 3,7-diamino-2,8-dimethyl-5-phenyl phenazinium chloride by AgCl and Ag nanoparticles, J. Lumin., 2007, 126, 155–159.

    Article  CAS  Google Scholar 

  21. K. M. Glenn, R. M. Palepu, Fluorescence probing of aerosol OT based reverse micelles and microemulsions in n-alkanes (C6–C16) and quenching of Safranine-T in these systems, J. Photochem. Photobiol., A, 2006, 179, 283–288.

    Article  CAS  Google Scholar 

  22. R. Chaudhuri, P. K. Sengupta, K. K. Rohatgi Mukherjee, Luminescence behaviour of phenosafranin in reverse micelles of AOT in n-heptane, J. Photochem. Photobiol., A, 1997, 108, 261–265.

    Article  CAS  Google Scholar 

  23. A. Niazi, A. Yazdanipour, J. Ghasemi, M. Kubista, Spectrophotometric and thermodynamic study on the dimerization equilibrium of ionic dyes in water by chemometrics method, Spectrochim. Acta, Part A, 2006, 65, 73–78.

    Article  Google Scholar 

  24. I. A. Pastre, M. G. Neumann, The effect of microheterogeneous domains in the protonation of the triplet state of safranine-T, J. Colloid Interface Sci., 1996, 179, 227.

    Article  CAS  Google Scholar 

  25. C. M. Previtali, S. G. Bertolotti, M. G. Neumann, I. A. Pastre, A. M. Rufs, M. V. Encinas, Laser Flash Photolysis Study of the Photoinitiator System for Vinyl Polymerization: Safranine T - Aliphatic Amines, Macromolecules, 1994, 27, 7454–58.

    Article  CAS  Google Scholar 

  26. M. V. Encinas, A. M. Rufs, M. G. Neumann, C. M. Previtali, Photoinitiated Vinyl Polymerization by Safranine T/triethanolamine in Aqueous Solution, Polymer, 1996, 37, 1395–1398

    Article  CAS  Google Scholar 

  27. M. L. Gómez, V. Avila, H. A. Montejano, C. M. Previtali, A mechanistic and laser flash photolysis investigation of acrylamide polymerization photoinitiated by the three component system safranine-T/triethanolamine/diphenyliodonium chloride, Polymer, 2003, 44, 2875–2881

    Article  Google Scholar 

  28. M. L. Gómez, H. A. Montejano, M. Bohorquez, C. M. Previtali, Photopolymerization of acrylamide initiated by the three component system safranine/triethanolamine/diphenyliodonium chloride. The effect of aggregation of the salt, J. Polym. Sci., Part A: Polym. Chem., 2004, 42, 4916–4920

    Article  Google Scholar 

  29. M. L. Gómez, C. M. Previtali, H. A. Montejano, Phenylonium salts as third component of the photoinitiator system safranine O/triethanolamine: A comparative study in aqueous media, Polymer, 2007, 48, 2355-236.

    Article  Google Scholar 

  30. E. R. Macias, L. A. Rodríguez-Guadarrama, B. A. Cisneros, A. Castañeda, E. Mendizábal, J. E. Puig, Microemulsion polymerization of methyl methacrylate with the functional monomer N-methylolacrylamide, Colloids Surf., A, 1995, 103, 119–126

    Article  CAS  Google Scholar 

  31. I. Capek, On the role of oil-soluble initiators in the radical polymerization of micellar systems, Adv. Colloid Interface Sci., 2001, 91, 295–334

    Article  CAS  Google Scholar 

  32. K. Trickett, J. Eastoe, Surfactant-based gels, Adv. Colloid Interface Sci., 2008, 144, 66–74

    Article  CAS  Google Scholar 

  33. B. Schulz, I. Orgzall, I. Díez, B. Dietzel, K. Tauer, Template mediated formation of shaped polypyrrole particles, Colloids Surf., A, 2010, 354, 368–376.

    Article  CAS  Google Scholar 

  34. M. Hasegawa, Buffer-like Action in Water Pool of Aerosol OT Reverse Micelles, Langmuir, 2001, 17, 1426–1431.

    Article  CAS  Google Scholar 

  35. H. A. Montejano, M. Gervaldo, S. G. Bertolotti, The excited-states quenching of resazurin and resorufin by p-benzoquinones in polar solvents, Dyes Pigm., 2005, 64, 117–124.

    Article  CAS  Google Scholar 

  36. M. L. Gómez, C. M. Previtali, H. A. Montejano, Photophysical properties of safranine O in protic solvents, Spectrochim. Acta, Part A, 2004, 60, 2433–2439.

    Article  Google Scholar 

  37. M. Hasegawa, A. Kitahara, Microviscosity in water pool of Aerosol-OT reversed micelle determined with viscosity-sensitive fluorescence probe, auramine O, and fluorescence depolarization of xanthene dyes, J. Phys. Chem., 1994, 98, 2120–2124.

    Article  CAS  Google Scholar 

  38. M. Hasegawa, Buffer-like Action in Water Pool of Aerosol OT Reverse Micelles, Langmuir, 2001, 17, 1426–1431.

    Article  CAS  Google Scholar 

  39. C. D. Borsarelli, S. G. Bertolotti, C. M. Previtali, Thermodynamic changes in the photoinduced proton-transfer reaction of the triplet state of safranine-T, Photochem. Photobiol. Sci., 2002, 1, 574–580.

    Article  CAS  Google Scholar 

  40. J. Sangster, Octanol-water Partition Coefficients: fundamentals and physical chemistry, John Wiley & Sons, Chichester (1997) p. 161.

    Google Scholar 

  41. D. Grand, Electron Transfer in Reverse Micellar Solutions: Influence of the Interfacial Bound Water, J. Phys. Chem. B, 1998, 102, 4322–4326.

    Article  CAS  Google Scholar 

  42. S. S. Atik, J. K. Thomas, Transport of Photoproduced Ions in Water in Oil Microemulsions: Movement of Ions from One Water Pool to Another, J. Am. Chem. Soc., 1981, 103, 3543–3550.

    Article  CAS  Google Scholar 

  43. D. M. Togashi, S. M. B. Costa, Excited state quenching kinetics of zinc meso-tetrakis (N-methylpyridinium-4-yl) porphyrin by methyl viologen in AOT reverse micelles, Phys. Chem. Chem. Phys., 2002, 4, 1141–1150.

    Article  CAS  Google Scholar 

  44. M. V. Encinas, C. M. Previtali, S. G. Bertolotti, M. G. Neumann, The interaction of the excited states of safranine T with aliphatic amines in organic solvents, Photochem. Photobiol., 1995, 62, 65–70.

    Article  CAS  Google Scholar 

  45. L. Zingaretti, N. M. Correa, L. Boscatto, S. M. Chiacchiera, E. Durantini, S. G. Bertolotti, C. R. Rivarola, J. J. Silber, Distribution of amines in water/AOT/n-hexane reverse micelles: influence of the amine chemical structure, J. Colloid Interface Sci., 2005, 286, 245–252.

    Article  CAS  Google Scholar 

  46. M. F. Broglia, S. G. Bertolotti, C. M. Previtali, Proton and Electron Transfer in the Excited State Quenching of Phenosafranine by Aliphatic Amines, Photochem. Photobiol., 2007, 83, 535–541.

    Article  CAS  Google Scholar 

  47. J. J. Silber, A. Biasutti, E. Abuin, E. Lissi, Interactions of small molecules with reverse micelles, Adv. Colloid Interface Sci., 1999, 82, 189–252.

    Article  CAS  Google Scholar 

  48. S. N. Guha, J. P. Mittal, Pulse radiolysis study of one-electron reduction of safranine T, J. Chem. Soc., Faraday Trans., 1997, 93, 3647.

    Article  CAS  Google Scholar 

  49. R. Bonneau, I. Carmichael, G. L. Hug, Molar absorption coefficients of transient species in solution, Pure Appl. Chem., 1991, 63, 289–299.

    Article  CAS  Google Scholar 

  50. M. V. Encinas, E. A. Lissi, A. M. Rufs, C. M. Previtali, Polymerization photoinitiated by carbonyl compounds. X. Methyl, methacrylate polymerization photoinitiated by fluorenone in the presence of triethylamine, J. Polym. Sci., Part A: Polym. Chem., 1994, 32, 1649–1655

    Article  CAS  Google Scholar 

  51. C. M. Previtali, S. G. Bertolotti, M. G. Neumann, I. A. Pastre, A. M. Rufs, M. V. Encinas, Laser flash photolysis of the photoinitiator system for vinyl polymerization: safranine T - aliphatic amines, Macromolecules, 1994, 27, 7454–58.

    Article  CAS  Google Scholar 

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Correspondence to Carlos M. Previtali.

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Porcal, G.V., Chesta, C.A., Biasutti, M.A. et al. Quenching of the triplet state of safranine-O by aliphatic amines in AOT reverse micelles studied by transient absorption spectroscopy. Photochem Photobiol Sci 11, 302–308 (2012). https://doi.org/10.1039/c1pp05252g

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