Photophysical properties of 7-diethylaminocoumarin dyes in dioxane–water mixtures: hydrogen bonding, dielectric enrichment and polarity effects

Abstract

The effect of water on the photophysical properties of four 7-diethylaminocoumarin dyes (AC 1, BC I, BC II and C 35) in dioxane–water solvent mixtures is studied. Dielectric enrichment of the dyes is not observed in the binary mixtures. Rate constants for bimolecular quenching are calculated. BC I and C 35 are found to undergo both static and dynamic quenching while only static quenching is observed in the case of BC II. The association constant is however found to be very small (K_b=2–5×10^-2 M^-1). No such dependence is observed in AC 1 where the formation of an intramolecular hydrogen bond is strongly favored. The increase in the non-radiative rate constant with the water concentration observed in the other three dyes (BC I, BC II and C 35) can be correlated to the solvent polarity and hydrogen bonding parameter E_T(30). A threshold value of the solvent polarity–polarizability parameter (Pekar factor C) for the non-radiative process is observed for all these three dyes and it is nearly independent of the nature of substitution. The photophysical properties of AC 1 can be adequately explained by considering only one singlet excited state while an additional singlet excited state needs to be included to understand the photophysics of BC I, BC II and C 35 in highly polar environments.

References

1. (a) K. H. Drexhage, in Dye Lasers, Topics in Applied Physics, ed. F. P. Schäfer, Springer Verlag, New York, 2nd edn., 1977, vol. 1; (b) C. R. Moylan, J. Phys. Chem., 1994, 98, 13513; (c) M. L. Horng, G. A. Gardecki, A. Papazyan and A. and M. Maroncelli, J. Phys. Chem., 1995, 99, 17311; (d) N. Sarkar, A. Datta, S. Das and K. Bhattacharyya, J. Phys. Chem., 1996, 100, 15483.
2. G. Jones II, W. R. Jackson and A. M. Halpern, Chem. Phys. Lett., 1980, 72, 391.
3. G. Jones II, W. R. Jackson, C.-Y. Choi and W. R. Bergmark, J. Phys. Chem., 1985, 89, 294.
4. K. Rechthaler and G. Köhler, Chem. Phys., 1994, 189, 99 and references therein.
5. B. B. Raju, J. Phys. Chem., 1997, 101A, 981 and references therein.
6. (a) T. L. Arbeloa, F. L. Arbeloa, M. J. Tapia and I. L. Arbeloa, J. Phys. Chem., 1993, 97, 4704; (b) T. L. Arbeloa, F. L. Arbeloa and I. L. Arbeloa, J. Lumin., 1996, 68, 149.
7. T. Gustavsson, L. Cessaro, V. Gulbinas, G. Gurzadyan, J.-C. Mialocq, S. Pommert, M. Sorgins and P. van der Muelen, J. Phys. Chem., 1998, 102A, 4229.
8. (a) R. W. Yip and Y.-X. Wen, Can. J. Chem., 1991, 69, 1413; (b) R. W. Yip and Y.-X. Wen, Can. J. Chem., 1991, 69, 2142; (c) R. W. Yip, Y.-X. Wen and A. G. Szabo, J. Phys. Chem., 1993, 97, 10458.
9. Z. R. Grabowski, K. Rotkiewicz, A. Siemiarczuk, D. Cowley and W. Baumann, Nouv. J. Chim., 1979, 3/7, 443.
10. (a) E. Lippert, Z. Naturforsch., 1955, 10A, 541; (b) N. Mataga, Y. Kaifu and M. Azumi, Bull. Chem. Soc. Jpn., 1956, 29, 465.
11. C. Reichardt, Solvents and solvent effects in organic chemistry, VCH, Weinheim, 1988.
12. M. J. Kamlet, C. Dickinson and R. W. Taft, Chem. Phys. Lett., 1981, 77, 69.
13. N. A. Nemkovich, W. Baumann, H. Reis and Y. Z. Zvinevich, J. Photochem. Photobiol. A, 1997, 109, 287.
14. M. Bellête, G. Lessard and G. Durocher, J. Lumin., 1989, 42, 337.
15. C. A. T. Laia and S. M. B. Costa, Chem. Phys. Lett., 1998, 285, 385.
16. (a) J. Arden-Jacob, N. J. Marx and K. H. Drexhage, J. Fluoresc., 1997, 7, 91S (Supplement); (b) A. N. Fletcher, Photochem. Photobiol., 1975, 12, 1061.
17. D. V. O'Connor and D. Phillips, in Time-correlated single photon counting, Academic Press, New York, 1984, ch. 6.
18. J. S. S. de Melo, R. S. Becker and A. L. Maçanita, J. Phys. Chem., 1994, 98, 6054.
19. S. P. Van and G. S. Hammond, J. Am. Chem. Soc., 1978, 100, 3895.
20. J. Midwinter and P. Suppan, Spectrochim. Acta, 1969, 25A, 953.
21. P. Suppan, J. Chem. Soc., Faraday Trans. 1, 1987, 83, 495.
22. F. E. Critchfield, J. A. Gibson, Jr. and J. L. Hall, J. Am. Chem. Soc., 1953, 75, 1991.
23. G. Jones II, W. R. Jackson, S. Kanoktanaporn and W. R. Bergmark, Photochem. Photobiol., 1985, 42, 477.
24. K. Ibuki and M. Nakahara, J. Chem. Phys., 1986, 84, 6979.
25. J. R. Lackowicz, in Principles of fluorescence spectroscopy, Plenum, New York, 1986, ch. 9.
26. A. L. Maçanita, F. P. Costa, S. M. B. Costa, E. C. Melo and H. Santos, J. Phys. Chem., 1989, 93, 336.
27. (a) T. L. Nemzek and W. R. Ware, J. Chem. Phys., 1975, 62, 477; (b) J. C. Andre, M. Niclause and W. R. Ware, Chem. Phys., 1978, 28, 371.
28. G. Atkinson, S. Rajagopalan and B. L. Atkinson, J. Chem. Phys., 1980, 72, 3511.
29. S. Mashimo, N. Miura, T. Umehara, S. Yagihara and K. Higasi, J. Chem. Phys., 1992, 96, 6358.
30. J. B. Birks, Photophysics of Aromatic Molecules, Wiley-Interscience, NY, 1970.
31. U. Leinhos, W. Kühnle and K. Zachariasse, J. Phys. Chem., 1991, 95, 2013.
32. (a) H. J. Kim and J. T. Hynes, J. Photochem. Photobiol. A, 1997, 105, 337; (b) R. A. Marcus, J. Chem. Phys., 1965, 43, 679; (c) R. A. Marcus and N. Sutin, Biochim. Biophys. Acta, 1985, 811, 265.
33. (a) J. M. Hicks, M. T. Vandersall, Z. Babarogic and K. B. Eisenthal, Chem. Phys. Lett., 1985, 116, 18; (b) J. M. Hicks, M. T. Vandersall, E. V. Sitzman and K. B. Eisenthal, Chem. Phys. Lett., 1987, 135, 413.
34. N. Sarkar, K. Das, D. N. Nath and K. Bhattacharyya, Langmuir, 1994, 10, 326.
35. K. Das, N. Sarkar, D. N. Nath and K. Bhattacharyya, Spectrochim. Acta, 1992, 48A, 1701.
36. B. B. Raju and S. M. B. Costa, J. Phys. Chem., 1999, 103B, 4309.
37. P. K. McCarthy and G. J. Blanchard, J. Phys. Chem., 1993, 97, 12205.
38. P. K. I. Priyadarshini, D. B. Naik and P. N. Moorthy, Chem. Phys. Lett., 1988, 148, 572.
39. R. V. Sahyun and D. K. Sharma, Chem. Phys. Lett., 1992, 189, 571.
40. P. Sprecht, P. A. Martic and S. Farid, Tetrahedron, 1982, 38, 1203.
41. R. S. Becker, S. Chakravorti, G. Gartner and M. de G. Miguel, J. Chem. Soc., Faraday Trans., 1993, 89, 1007.
42. B. B. Raju and B. Eliasson, J. Photochem. Photobiol. A, 1998, 116, 135.