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Mechanism and dynamics of intramolecular triplet state decay of 1-propyl-4-thiouracil and its α-methyl-substituted derivatives studied in perfluoro-1,3-dimethylcyclohexane

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Abstract

The absorption, phosphorescence and phosphorescence excitation spectra, phosphorescence quantum yields, and T1 excited state lifetimes of four 4-thiouracil derivatives were measured for the first time in chemically inert and very weakly interacting perfluoro-1,3-dimethylcyclohexane at room temperature. The set of the 4-thiouracil derivatives comprises 1-propyl-4-thiouracil (PTU) and the related compounds having a methyl substituent at the position α to the thiocarbonyl group, namely 1-propyl-4-thiothymine (PTT), 1,3-dimethyl-4-thiouracil (DMTU), and 1-methyl-3-trideuteriomethyl-4-thiouracil ([D3]DMTU). Quantitative information on the intramolecular decay of the T1 excited state of the four 4-thiouracil derivatives is presented, and the mechanism and dynamics of this process are discussed. In the absence of self quenching and solvent induced deactivation, the T1 decay of the four 4-thiouracil derivatives was dominated by intramolecular nonradiative processes (NR). The values of the rate constant kNR in DMTU and [D3]DMTU are about 4 times larger than that in PTT and about 3 times larger than that in PTU. The reasons for the enhanced nonradiative rate constant in DMTU are discussed. It is concluded that the faster rate of the nonradiative processes in DMTU is related to a larger contribution from mixing of the T2 (nπ*) state into the lowest energy T1 (ππ*) state, as compared to the analogous coupling in PTU and PTT. This conclusion is supported by ab initio calculations performed at the EOM-CC2/aug-cc-pVDZ level of theory. The energy spacing between the T2 (nπ*) and T1 (ππ*) states is estimated to be about 500, 1100, and 2000 cm−1 for DMTU, PTU, and PTT, respectively. Among the three compounds in question, the predicted energy spacing is thus the smallest for DMTU.

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References

  1. A. Frazel-Abel and P. J. Hagerman, Variation of the acceptor- anticodon interstem angles among mitochondrial and non- mitochondrial tRNAs, J. Mol. Biol., 2004, 343, 313–325

    Article  CAS  Google Scholar 

  2. A. Favre and G. Thomas, Transfer RNA: From photophysics to photobiology, Annu. Rev. Biophys. Bioeng., 1981, 10, 175–195.

    Article  CAS  PubMed  Google Scholar 

  3. A. Favre, 4-Thiouridine as an intrinsic photoaffinity probe of nucleic acid structure and interactions in Bioorganic photochemistry, ed. H. Morrison, Wiley, New York, 1990, vol. 1, pp. 379–425.

    CAS  Google Scholar 

  4. A. Favre, C. Saintome, J.-L. Fourrey, P. Clivio and P. Laugaa, Thionucleobases as intrinsic photoaffinity probes of nucleic acid structure and nucleic acid-protein interactions, J. Photochem. Photobiol., B, 1998, 42, 109–124.

    Article  CAS  Google Scholar 

  5. K. M. Meisenheimer and T. H. Koch, Photocrosslinking of nucleic acids to associated proteins, Crit. Rev. Biochem. Mol. Biol., 1997, 32, 101–140.

    Article  CAS  PubMed  Google Scholar 

  6. D. Temiakov, M. Anilin, K. Ma, M. Jiang and W. T. McAllister, Probing the organization of transcription complexes using photoreactive 4-thiosubstituted analogs of uracil and thymidine, Methods Enzymol., 2003, 371, 133–143

    Article  CAS  PubMed  Google Scholar 

  7. C. L. Chepanoske, O. A. Lukianova, M. Lombard, M.-P. Golinelli-Cohen and S. S. David, A residue in MutY important for catalysis identified by photocross-linking and mass spectrometry, Biochemistry, 2004, 43, 651–662.

    Article  CAS  PubMed  Google Scholar 

  8. A. Massey, Y.-Z. Xu and P. Karran, Photoactivation of DNA thiobases as a potential novel therapeutic option, Curr. Biol., 2001, 11, 1142–1146

    Article  CAS  PubMed  Google Scholar 

  9. X. Zhang, G. Jeffs, X. Ren, P. O’Donovan, B. Montaner, C. M. Perret, P. Karran and Y.-Z. Xu, Novel DNA lesions generated by the interaction between therapeutic thiopurines and UVA light, DNA Repair, 2007, 6, 344–354

    Article  CAS  PubMed  Google Scholar 

  10. C. Reelfs, Y.-Z. Xu, A. Massey, P. Karran and A. Storey, Thiothymidine plus low-dose UVA kills hyperproliferative human skin cells independently of their papilloma virus status, Mol. Cancer Ther., 2007, 6, 2487–2495.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. K. Heihoff, R. W. Redmond, S. E. Braslavsky, M. Rougee, C. Salet, A. Favre and R. V. Benssason, Quantum yields of triplet and O21Δg) formation of 4-thiouridine in water and acetonitrile, Photochem. Photobiol., 1990, 51, 635–641.

    Article  CAS  PubMed  Google Scholar 

  12. Y. Harada, T. Suzuki, T. Ichimura and Y.-Z. Xu, Triplet formation of 4-thiothymidine and its photosensitization to oxygen studied by time-resolved thermal lensing technique, J. Phys. Chem. B, 2007, 111, 5518–5524.

    Article  CAS  PubMed  Google Scholar 

  13. S. J. Milder and D. S. Klieger, Spectroscopy and photochemistry of thiouracils: Implications for the mechanism of photocrosslinking in tRNA, J. Am. Chem. Soc., 1985, 107, 7365–7373.

    Article  CAS  Google Scholar 

  14. K. Taras-Goslinska, G. Wenska, B. Skalski, A. Maciejewski, G. Burdzinski and J. Karolczak, Intra- and intermolecular electronic relaxation of the second excited singlet and the lowest excited triplet states of 1,3-dimethyl-4-thiouracil in solution, Photochem. Photobiol., 2002, 75, 448–465.

    Article  CAS  Google Scholar 

  15. K. Taras-Goslinska, G. Wenska, B. Skalski, A. Maciejewski, G. Burdzinski and J. Karolczak, Spectral and photophysical properties of the lowest excited triplet state of 4-thiouridine and its 5-halogeno derivatives, J. Photochem. Photobiol., A, 2004, 168, 227–233.

    Article  CAS  Google Scholar 

  16. G. Wenska, J. Koput, G. Burdzinski, K. Taras-Goslinska and A. Maciejewski, Photophysical and photochemical properties of the T1 excited state of thioinosine, J. Photochem. Photobiol., A, 2009, 206, 93–101.

    Article  CAS  Google Scholar 

  17. G. Wenska, K. Taras-Goslinska, B. Skalski, A. Maciejewski, G. Burdzinski and J. Karolczak, Putative phototautomerization of 4-thiouridine in the S2 excited state revealed by fluorescence study using picosecond laser spectroscopy, J. Photochem. Photobiol., A, 2006, 181, 12–18.

    Article  CAS  Google Scholar 

  18. Y. Harada, C. Okabe, T. Kobayashi, T. Suzuki, T. Ichimura, N. Nishi and Y.-Z. Xu, Ultrafast intersystem crossing of 4-thiothymidine in aqueous solution, J. Phys. Chem. Lett., 2010, 1, 480–484.

    Article  CAS  Google Scholar 

  19. C. Reichardt and C. E. Crespo-Hernandez, Room-temperature phosphorescence of the DNA monomer analogue 4-thiothymidine in aqueous solutions after UVA excitation, J. Phys. Chem. Lett., 2010, 1, 2239–2243

    Article  CAS  Google Scholar 

  20. C. Reichardt and C. E. Crespo-Hernandez, Ultrafast spin crossover in 4-thiothymidine in an ionic liquid, Chem. Commun., 2010, 46, 5963–5965.

    Article  CAS  Google Scholar 

  21. M. Milewski, J. Baksalary, P. Antkowiak, W. Augustyniak, M. Binkowski, J. Karolczak, D. Komar, A. Maciejewski, M. Szymański and W. Urjasz, Deactivation of the S2 and two lowest triplet states of 4H-1-benzopyran-4-thione and its alkyl derivatives in methanol solution, J. Fluoresc., 2000, 10, 89–97.

    Article  CAS  Google Scholar 

  22. A. Maciejewski, M. Szymanski and R. P. Steer, Photochemistry and photophysics of thione triplets in fluid solution, J. Phys. Chem., 1988, 92, 6939–6944.

    Article  CAS  Google Scholar 

  23. M. Szymanski, A. Maciejewski and R. P. Steer, Photophysics of thione triplets in solution: factors controlling the rates of radiationless decay, Chem. Phys., 1988, 124, 143–154.

    Article  CAS  Google Scholar 

  24. A. Maciejewski, A. Safarzadeh-Amiri, R. E. Verrall and R. P. Steer, Radiationless decay of the second excited singlet states of aromatic thiones: experimental verification of the energy gap law, Chem. Phys., 1984, 87, 295–303

    Article  CAS  Google Scholar 

  25. A. Maciejewski, D. R. Demmer, D. R. James, A. Safarzadeh-Amiri, R. E. Verrall and R. P. Steer, Relaxation of the second excited singlet states of aromatic thiones: the role of specific solute-solvent interactions, J. Am. Chem. Soc., 1985, 107, 2831–2837

    Article  CAS  Google Scholar 

  26. A. Maciejewski and R. P. Steer, Effect of solvent on the subnanosecond decay of the second excited singlet state of tetramethylindanethione, Chem. Phys. Lett., 1983, 100, 540–545

    Article  CAS  Google Scholar 

  27. A. Maciejewski and R. P. Steer, Photophysics of the second excited singlet states of xanthione and related thiones in perfluoroalkane solvents, J. Am. Chem. Soc., 1983, 105, 6738–6740

    Article  CAS  Google Scholar 

  28. C.-J. Ho, L. Motyka and M. R. Topp, Picosecond time-resolved S2→S0 fluorescence of xanthione in different fluid solvents, Chem. Phys. Lett., 1989, 158, 51–59

    Article  CAS  Google Scholar 

  29. A. M. Mahaney and J. R. Huber, Solvent effect on the non-radiative S2(ππ*) decay of xanthione, Chem. Phys. Lett., 1984, 105, 395–399.

    Article  CAS  Google Scholar 

  30. G. Burdzinski, A. Maciejewski, G. Buntinx, O. Poizat and C. Lefumeux, Ultrafast quenching of the excited S2 state of benzopyranthione by acetonitrile, Chem. Phys. Lett., 2004, 384, 332–338.

    Article  CAS  Google Scholar 

  31. A. Maciejewski, The application of perfluoroalkanes as solvents in spectral, photophysical and photochemical studies, J. Photochem. Photobiol., A, 1990, 51, 87–131.

    Article  CAS  Google Scholar 

  32. C. A. Parker and T. A. Joyce, Triplet behaviour in fluorocarbon solvents, Trans. Faraday Soc., 1969, 65, 2823–2829

    Article  CAS  Google Scholar 

  33. H. Tsubomura, N. Yamamoto and S. Tanaka, Transient absorption spectra of ben-zophenone studied by the flash excitation, Chem. Phys. Lett., 1967, 1, 309–310

    Article  CAS  Google Scholar 

  34. M. Kamachi, Y. Kikuta and S. Nozura, Polymer effect on the photochemical reaction of benzophenone with tetrahydrofuran and with diphenylamine in benzene, Polym. J., 1979, 11, 273–277.

    Article  CAS  Google Scholar 

  35. R. Rejee and V. Ramamurthy, Energy wastage in organic photochem istry: self-quenching in thiones, J. Photochem. Photobiol. A, 1979, 11, 135–138

    Google Scholar 

  36. K. Bhattacharyya, P. K. Das, V. Ramamurthy and P. Rao, Triplet-state and transient photochemistry of cyclic enethiones, J. Chem. Soc., Faraday Trans. 2, 1986, 82, 135–147

    Article  CAS  Google Scholar 

  37. A. Safarezadeh-Amiri, R. E. Verrall and R. P. Steer, Decay dynamics of aromatic thione triplet states in fluid solution, Can. J. Chem., 1983, 61, 894–900.

    Article  Google Scholar 

  38. M. Szymanski, A. Maciejewski, J. Kozłowski and J. Koput, Photo-physics of the S2 state of thiocoumarin: a vibrationally unequilibrated luminophore, J. Phys. Chem., 1998, 102, 677–683; M. Milewski, Ph.D. Dissertation, A. Mickiewicz University, Poznan, Poland, 1998.

    Article  CAS  Google Scholar 

  39. M. Etinski and C. M. Marian, Ab initio investigation of the metylation and hydration effects on the electronic spectra of uracil and thymine, Phys. Chem. Chem. Phys., 2010, 12, 4915–4923.

    Article  CAS  PubMed  Google Scholar 

  40. J. Kubicki, A. Maciejewski, M. Milewski, T. Wrozowa and R. P. Steer, The relaxation of electronically excited molecules: effects of alkyl substitution on the S2 and T1 states of benzopyranthione in solution, Phys. Chem. Chem. Phys., 2002, 4, 173–179.

    Article  CAS  Google Scholar 

  41. A. Maciejewski and R. P. Steer, The photophysics, physical photochemistry, and related spectroscopy of thiocarbonyls, Chem. Rev., 1993, 93, 67–98.

    Article  CAS  Google Scholar 

  42. H. Eisenberger, B. Nickel, A. A. Ruth and R. P. Steer, Photophysical triplet state processes of 4-H-1-benzopyrane-4-thione in a perfluo-roalkane: Part 2. Delayed S2 → S0 fluorescence due to triplet-triplet annihilation, J. Chem. Soc., Faraday Trans., 1996, 92, 741–746.

    Article  CAS  Google Scholar 

  43. A. Maciejewski, M. Szymanski and R. P. Steer, T1-T2 inversion in aromatic thiones, Chem. Phys. Lett., 1988, 143, 559–564.

    Article  CAS  Google Scholar 

  44. M.-R. Taherian and A. H. Maki, Optically detected magnetic resonance study of the phosphorescent states of thiouracils, Chem. Phys., 1981, 55, 85–96.

    Article  CAS  Google Scholar 

  45. M. K. Shukla and J. Leszczyński, Multiconfigurational self-consistent field study of the excited state properties of 4-thiouracil in the gas phase, J. Phys. Chem. A, 2004, 108, 7241–7246

    Article  CAS  Google Scholar 

  46. M. K. Shukla and J. Leszczyński, Electronic transitions of thiouracils in the gas phase and in solutions: Time-Dependent Density Functional Theory (TD-DFT) study, J. Phys. Chem. A, 2004, 108, 10367–10375.

    Article  CAS  Google Scholar 

  47. G. Burdzinski, G. Buntinx, O. Poizat and C. Lapouge, Time-resolved resonance Raman investigation and ab initio calculations of the T1-state structure of thiocoumarin, J. Mol. Struct., 2005, 735-736, 115–122.

    Article  CAS  Google Scholar 

  48. A. Maciejewski, M. Szymanski and R. P. Steer, The photophysics of thioflavone in solution, J. Photochem. Photobiol., A, 1996, 100, 43–52.

    Article  CAS  Google Scholar 

  49. A. Maciejewski, M. Szymanski and R. P. Steer, Radiationless decay of aromatic thiones in solution selectively excited to their S3, S2, S1 and T1 states, J. Phys. Chem., 1988, 92, 2485–2489

    Article  Google Scholar 

  50. A. Maciejewski, M. Szymanski and R. P. Steer, Thermally activated delayed S1 fluorescence of aromatic thiones, J. Phys. Chem., 1986, 90, 6314–6318.

    Article  CAS  Google Scholar 

  51. S. R. Abrams, M. Green, R. P. Steer and M Szymański, Unusual deuterium isotope effect on the radiationless decay of xanthione S2, Chem. Phys. Lett., 1987, 139, 182–186.

    Article  CAS  Google Scholar 

  52. S. Yamauchi, K. Mibu, Y. Komada and N. Hirota, Temperature dependence of the triplet lifetimes of methylpyrazines. Proximity effect, J. Phys. Chem., 1987, 91, 6173–6177.

    Article  CAS  Google Scholar 

  53. N. J. Turro, V. Ramamurthy, J. C. Scaiano, Modern Molecular Photochemistry of Organic Molecules, University Science Books, 2010, pp. 240–243.

    Google Scholar 

  54. S. J. Milder, P. S. Weiss and D. S. Kliger, Time-resolved absorption, circular dichroism, and emission of tRNA. Evidence, that the photo-cross-linking of 4-thiouridine in tRNA occurs from the triplet state, Biochemistry, 1989, 28, 2258–2264.

    Article  CAS  PubMed  Google Scholar 

  55. R. S. Meech and D. Phillips, Photophysics of some common fluorescence standards, J. Photochem., 1983, 23, 193–217.

    Article  CAS  Google Scholar 

  56. S. L. Murov, I. Carmichael, G. L. Hug, Handbook of Photochemistry, 2nd ed., Marcel Dekker, New York, 1993, p. 313.

    Google Scholar 

  57. T. Brown, J. Eisinger and N. J. Leonard, Synthetic spectroscopic models related to coenzymes and base pairs. II. Evidence for intramolecular base-base interactions in dinucleotide analogs, J. Am. Chem. Soc., 1968, 90, 7302–7323.

    Article  Google Scholar 

  58. C. Moeller and M. S. Plesset, Note on the approximation treatment for many-electron systems, Phys. Rev., 1934, 46, 618–622.

    Article  Google Scholar 

  59. M. Head-Gordon, R. J. Rico, M. Oumi and T. J. Lee, A doubles correction to electronic excited states from configuration interaction in the space of single substitutions, Chem. Phys. Lett., 1994, 219, 21–29.

    Article  CAS  Google Scholar 

  60. T. H. Dunning Jr., Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen, J. Chem. Phys., 1989, 90, 1007–1023.

    Article  CAS  Google Scholar 

  61. R. A. Kendall, T. H. Dunning Jr. and R. J. Harrison, Electron affinities of the first-row atoms revisited. Systematic basis sets and wave functions, J. Chem. Phys., 1992, 96, 6796–6806.

    Article  CAS  Google Scholar 

  62. J. F. Stanton and R. J. Bartlett, The equation of motion coupled-cluster method. A systematic biorthogonal approach to molecular excitation energies, transition probabilities, and excited state properties, J. Chem. Phys., 1993, 98, 7029–7040.

    Article  CAS  Google Scholar 

  63. O. Christiansen, H. Koch and P. Jørgensen, The second-order approximate coupled cluster singles and doubles model CC2, Chem. Phys. Lett., 1995, 243, 409–418.

    Article  CAS  Google Scholar 

  64. CFOUR, a quantum-chemical program package by J. F. Stanton, J. Gauss, M. E. Harding, P. G. Szalay, with contributions from A. A. Auer, R. J. Bartlett, U. Benedikt, C. Berger, D. E. Bernholdt, Y. J. Bomble, L. Cheng, O. Christiansen, M. Heckert, O. Heun, C. Huber, T. -C. Jagau, D. Jonsson, J. Jusélius, K. Klein, W. J. Laud-erdale, D. A. Matthews, T. Metzroth, D. P. O’Neill, D. R. Price, E. Prochnow, K. Ruud, F. Schiffmann, W. Schwalbach, S. Stopkowicz, A. Tajti, J. Vázquez, F. Wang, J. D. Watts, and the integral packages MOLECULE (J. Almlöf, and P. R. Taylor), PROPS (P. R. Taylor), ABACUS (T. Helgaker, H. J. A. Jensen, P. Jørgensen, and J. Olsen), and ECP routines by A. V. Mitin, and C. van Wüllen.

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Wenska, G., Taras-Goślińska, K., Łukaszewicz, A. et al. Mechanism and dynamics of intramolecular triplet state decay of 1-propyl-4-thiouracil and its α-methyl-substituted derivatives studied in perfluoro-1,3-dimethylcyclohexane. Photochem Photobiol Sci 10, 1294–1302 (2011). https://doi.org/10.1039/c1pp05034f

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