Skip to main content
Log in

Hydrogen bond assisted photoinduced intramolecular electron transfer and proton coupled electron transfer in an ultrafast time domain using a ruthenium-anthraquinone dyad†

  • Paper
  • Published:
Photochemical & Photobiological Sciences Aims and scope Submit manuscript

Abstract

Quinones play a significant role as primary electron acceptors in the natural photosynthetic system of photosystem II, and their reduction is known to be facilitated by hydrogen-bond donors or protonation. In this study, a ruthenium(II) polypyridyl complex 1 coupled to an anthraquinone (AQ) functionality through a rigid imidazole (Im) spacer has been synthesized to examine the effect of H-bonding on both the thermal and photoinduced electron transfer reactions. The anthraquinone moiety of complex 1 is fused to a benzi-imidazole system bearing C=OAQ⋯HNIm based H-bonding at one side of the anthraquinone moiety so that intramolecular hydrogen bonding from the imidazole group to the nearby quinone carbonyl can occur. The hydrogen bond formation involving the semiquinone radical anion produced through the photoinduced reduction process in Ru–im–AQ and the imidazole proton in complex 1 resulted in a significant positive shift of one electron reduction potential of complex 1. The kinetics for the formation of the charge-separated states was explored by using femtosecond transient absorption spectroscopy. Hydrogen bonding between water and the reduced anthraquinone accounted for thermodynamic and kinetic stabilization of these charge-separated states. An attempt has been made to assess the relative importance of the driving force and solvent polarity, in the rates of photoinduced electron transfer in complex 1. The 490 nm transient absorption band of anthraquinone radical anions (AQ•−) and a broad absorption in the 580–750 nm region having maxima at ~690 nm have been observed and this is attributed to the generation of a transient Ru3+-species of the corresponding complex 1. Addition of water entails an acceleration of electron transfer rates by a factor of 3.33. The system investigated may serve as a model for the mechanistic diversity of PCET reactions in general with water as a primary proton donor. Furthermore, our studies are relevant for understanding proton-coupled electron transfer (PCET) reactivity of electronically excited states at a fundamental level because changes in hydrogen-bonding strength accompanying changes in redox states may be regarded as a variant form of PCET.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Notes and references

  1. M. H. V. Huynh and T. J. Meyer, Proton Coupled Electron Transfer, Chem. Rev., 2007, 107, 5004–5064.

    Article  CAS  PubMed  Google Scholar 

  2. B. C. Westlake, M. K. Brennaman, J. J. Concepcion, J. J. Paul, S. E. Bettis, S. D. Hampton, S. A. Miller, N. V. Lebedeva, M. D. E. Forbes, A. M. Moran, T. J. Meyer and J. M. Papanikolas, Concerted electron-proton transfer in the optical excitation excitation of hydrogen-bonded dyes, Proc. Natl. Acad. Sci. U. S. A., 2011, 108, 8554–8558.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. M. D. Ward, Photo-induced electron and energy transfer in non-covalently bonded supramolecular assembly electrons, Chem. Soc. Rev., 1997, 26, 365.

    Article  CAS  Google Scholar 

  4. N. S. Sariciftci, L. Smilowitz, A. J. Heeger and F. Wudi, Photoinduced Electron Transfer from a Conducting Polymer to Buckminsterfullerene, Science, 1992, 258, 1474.

    Article  CAS  PubMed  Google Scholar 

  5. D. R. Weinberg, C. J. Gagliardi, J. F. Hull, C. F. Murphy, C. A. Kent, B. C. Westlake, A. Paul, D. H. Ess, D. Granville and T. J. Meyer, Photoinduced Electron Transfer from a Conducting Polymer to Buckminsterfullerene. Proton- Coupled Electron Transfer, Chem. Rev., 2012, 112, 4016.

    Article  CAS  PubMed  Google Scholar 

  6. Z. Liu, C. Tan, X. Guo, J. Li, L. Wang, A. Sancar and D. Zhong, Determining complete electron flow in the cofactor photoreduction of oxidized photolyase, Proc. Natl. Acad. Sci. U. S. A., 2013, 110, 12966.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. V. R. I. Kaila, M. I. Verkhovsky and M. Wikstro, Proton- Coupled Electron Transfer in Cytochrome Oxidase, Chem. Rev., 2010, 110, 7062.

    Article  CAS  PubMed  Google Scholar 

  8. T. Hino, Y. Matsumoto, S. Nagano, H. Sugimoto, Y. Fukumori, T. Murata, S. Iwata and Y. Shiro, Structural Basis of Biological N2O Generation by Bacterial Nitric Oxide Reductase, Science, 2010, 330, 1666.

    Article  CAS  PubMed  Google Scholar 

  9. Y. S. Kanan, D. G. N. Surendranath and M. W. Kanan, Cobalt–phosphate oxygen-evolving compound, Chem. Soc. Rev., 2009, 38, 109–114.

    Article  CAS  PubMed  Google Scholar 

  10. R. Gera, A. Das, A. Jha and J. Dasgupta, Light-Induced Proton Coupled Electron Transfer inside a nanocage, J. Am. Chem. Soc., 2014, 136, 4–7.

    Article  CAS  Google Scholar 

  11. J. Conyard, S. Haacke and Y. Me, Ultrafast photophysics of the environment- sensitive 40-methoxy-3-hydroxyflavone fluorescent dye, Phys. Chem. Chem. Phys., 2018, 20, 7885–7895.

    Article  PubMed  Google Scholar 

  12. S. K. Padhi, R. Fukuda, M. Ehara and K. Tanaka, Photoisomerization and Proton- Coupled Electron Transfer (PCET) Promoted Water Oxidation by Mononuclear Cyclometalated Ruthenium Catalysts, Inorg. Chem., 2012, 51, 5386.

    Article  CAS  PubMed  Google Scholar 

  13. G. Pourtois, D. Beljonne, J. Cornil, M. A. Ratner and J. L. Bre, Photoinduced Electron-Transfer Processes along Molecular Wires Based on Phenylenevinylene Oligomers: A Quantum-Chemical Insight, J. Am. Chem. Soc., 2002, 124, 4436–4447.

    Article  CAS  PubMed  Google Scholar 

  14. C. W. Hoganson and G. T. Babcock, Metalloradical Mechanism for the Generation Of Oxygen from Water in Photosynthesis, Science, 1997, 277, 1953.

    Article  CAS  PubMed  Google Scholar 

  15. T. Irebo, S. Y. Reece, M. Sjödin, D. G. Nocera and L. Hammarström, Proton-Coupled Electron Transfer of Tyrosine Oxidation: Buffer Dependence and Parallel Mechanisms, J. Am. Chem. Soc., 2007, 129, 15462.

    Article  CAS  PubMed  Google Scholar 

  16. T. J. Meyer, M. H. V. Huynh and H. H. Thorp, The Possible Role of Proton-Coupled Electron Transfer (PCET) in Water Oxidation by Photosystem II, Angew. Chem., Int. Ed., 2007, 46, 5284–5304.

    Article  CAS  Google Scholar 

  17. J. H. Hong, P. Dilbeck, R. J. Debus and R. L. Burnap, Mutation of Arginine 357 of the CP43 Protein of Photosystem II Severely Impairs the Catalytic S-State Cycle of the H2O Oxidation Complex, Biochemistry, 2007, 46, 11987.

    Article  CAS  Google Scholar 

  18. F. Lachaud, A. Quaranta, Y. Pellegrin, P. Dorlet, M. F. Charlot, S. Un, W. Leibl and A. Aukaulo, A Biomimetic Model of the Electron Transfer between P680 and the TyrZ–His190 Pair of PSII, Angew. Chem., Int. Ed., 2005, 44, 1536–1540.

    Article  CAS  Google Scholar 

  19. Y. Hu, S. Tsukiji, S. Shinkai, S. Oishi and I. Hamachi, Construction of Artificial Photosynthetic Reaction Centers on a Protein Surface: Vectorial, Multistep, and Proton- Coupled Electron Transfer for Long-Lived Charge Separation, J. Am. Chem. Soc., 2000, 122, 241.

    Article  CAS  Google Scholar 

  20. O. S. Wenger, Proton-Coupled Electron Transfer Originating from Excited States of Luminescent Transition- Metal Complexes, Chem.Eur. J., 2011, 17, 11692–11702.

    Article  CAS  PubMed  Google Scholar 

  21. K. N. Ferreira, T. M. Iverson, K. Maghlaoui and J. Barber, Architecture of the Photosynthetic Oxygen-Evolving Center, Science, 2004, 43, 1831–1839.

    Article  CAS  Google Scholar 

  22. A. A. Pizano, J. L. Yang and D. G. Nocera, Photochemical tyrosine oxidation with a hydrogen-bonded proton acceptor by bidirectional proton-coupled electron transfer, Chem. Sci., 2012, 3, 2457–2461.

    Article  CAS  PubMed  Google Scholar 

  23. C. J. Gagliardi, B. C. Westlake, C. A. Kent, J. J. Paul, J. M. Papanikolas and T. J. Meyer, Integrating proton coupled electron transfer (PCET) and excited states, Coord. Chem. Rev., 2010, 254, 2459–2471.

    Article  CAS  Google Scholar 

  24. S. Fukuzumi, K. Okamoto, Y. Yoshida, H. Imahori, Y. Araki and O. Ito, Effects of Hydrogen Bonding on Metal Ion- Promoted Intramolecular Electron Transfer and Photoinduced Electron Transfer in a Ferrocene-Quinone Dyad with a Rigid Amide Spacer, J. Am. Chem. Soc., 2003, 125, 1007.

    Article  CAS  PubMed  Google Scholar 

  25. A. Dey, J. Dana, S. Aute, P. Maity, A. Das and H. N. Ghosh, Proton-CoupledElectron- TransferProcesses in Ultrafast Time Domain:Evidence for Effects of Hydrogen-Bond Stabilization on Photoinduced Electron Transfer, Chem.Eur. J., 2017, 23, 3455.

    Article  CAS  PubMed  Google Scholar 

  26. J. Hankache and O. S. Wenger, Photoinduced electron transfer in covalent ruthenium–anthraquinone dyads: relative importance of driving-force, solvent polarity, and donor–bridge energy gap, Phys. Chem. Chem. Phys., 2012, 14, 2685–2692.

    Article  CAS  PubMed  Google Scholar 

  27. A. Babaei, P. A. Connor and A. J. McQuillan, UV-Visible Spectroelectrochemistry of Reduction Products of Anthraquinone in Dimethylformamide Solutions, J. Chem. Educ., 1997, 74, 1200–1204.

    Article  CAS  Google Scholar 

  28. S. Hammes-Schiffer, E. Hatcher, H. Ishikita, J. H. Skone and A. V. Soudackov, Theoretical studies of proton-coupled electron transfer: Models and concepts relevant to bioenergetics, Coord. Chem. Rev., 2008, 252, 384.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. V. W. Manner and J. M. Mayer, Concerted Proton-Electron Transfer in a Ruthenium Terpyridyl-Benzoate System with a Large Separation between the Redox and Basic Sites, J. Am. Chem. Soc., 2009, 131, 9874–9875.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. M. T. Zhang and L. Hammarström, Proton-Coupled Electron Transfer from Tryptophan: A Concerted Mechanism with Water as Proton Acceptor, J. Am. Chem. Soc., 2011, 133, 8806–8809.

    Article  CAS  PubMed  Google Scholar 

  31. D. Mondal and S. Baitalik, Design of Ruthenium Biimidazole-Anthraquinone Dyads to Demonstrate Photoinduced Electron Transfer: Combined Experimental and DFT/TD-DFT Investigations, ChemistrySelect, 2016, 1, 1318–1328.

    Article  CAS  Google Scholar 

  32. B. A. Barry, Free radicals under control, Nat. Chem., 2014, 6, 376–377.

    Article  CAS  PubMed  Google Scholar 

  33. N. Gupta and H. Linschitz, Hydrogen-Bonding and Protonation Effects in Electrochemistry of Quinones in Aprotic Solvents, J. Am. Chem. Soc., 1997, 7863, 6384.

    Article  Google Scholar 

  34. J. Hankache, D. Hanss and O. S. Wenger, Hydrogen-Bond Strengthening upon Photoinduced Electron Transfer in Ruthenium−Anthraquinone Dyads Interacting with Hexafluoroisopropanol or Water, J. Phys. Chem. A, 2012, 116, 3347–3358.

    Article  CAS  PubMed  Google Scholar 

  35. K. Kilså, J. Kajanus, A. N. Macpherson, J. Mårtensson, B. Albinsson, U. U. V. Albinsson and S. Umeå, Bridge- Dependent Electron Transfer in Porphyrin-Based Donor- Bridge-Acceptor Systems, J. Am. Chem. Soc., 2001, 123, 3069–3080.

    Article  PubMed  CAS  Google Scholar 

  36. J. Hankache and O. S. Wenger, Photoinduced electron transfer in covalent ruthenium–anthraquinone dyads: relative importance of driving-force, solvent polarity, and donor–bridge energy gapw, Phys. Chem. Chem. Phys., 2012, 14, 2685.

    Article  CAS  PubMed  Google Scholar 

  37. Y. Yuan, Y. Chen, Y. Wang, C. Su, S. Liang, H. Chao and L. Ji, Redox responsive luminescent switch based on a ruthenium(II) complex [Ru(bpy)2(PAIDH)]2+, Inorg. Chem. Commun., 2008, 11, 1048–1050.

    Article  CAS  Google Scholar 

  38. D. A. Jose, P. Kar, D. Koley, W. Thiel, H. N. Ghosh, A. Das, D. A. Jose, P. Kar, D. Koley, B. Ganguly and W. Thiel, Phenol- and Catechol-Based Ruthenium(II) Polypyridyl Complexes as Colorimetric Sensors for Fluoride Ions, Inorg. Chem., 2007, 46, 5576.

    Article  CAS  PubMed  Google Scholar 

  39. D. W. Thompson, A. Ito and T. J. Meyer, [Ru(bpy)3]2+ and other remarkable metal-to-ligand charge transfer (MLCT excited states*, Pure Appl. Chem., 2013, 85, 1257.

    Article  CAS  Google Scholar 

  40. E. Rajkumar, P. M. Mareeswaran and S. Rajagopal, Photophysical properties of amphiphilic ruthenium(II) complexes in micelles, Photochem. Photobiol. Sci., 2014, 13, 1261.

    Article  CAS  PubMed  Google Scholar 

  41. S. Verma, A. Das and H. N. Ghosh, Size Quantization Effects on Interfacial Electron Transfer Dynamics in Ru (II)−Polypyridyl Complex Sensitized ZnO QDs, J. Phys. Chem. C, 2014, 118, 28898–28905.

    Article  CAS  Google Scholar 

  42. S. L. Mecklenburg, C. Dewey, J. R. Schoonover, B. M. Peek, B. W. Erickson and T. J. Meyer, Spectroscopic Study of Electron Transfer in a Trifunctional Lysine with Anthraquinone as the Electron Acceptor, Inorg. Chem., 1994, 33, 2974.

    Article  CAS  Google Scholar 

  43. A. C. Bhasikuttan, M. Suzuki, S. Nakashima and T. Okada, Ultrafast Fluorescence Detection in Tris(2,2′-bipyridine) ruthenium(II) Complex in Solution: Relaxation Dynamics Involving Higher Excited States, J. Am. Chem. Soc., 2002, 8398–8405.

  44. S. Hung, A. N. Macpherson, S. Lin, P. A. Liddell, G. R. Seely, A. L. Moore, T. A. Moore and D. Gust, Coordinated Photoinduced Electron and Proton Transfer in a Molecular Triad, J. Am. Chem. Soc., 1995, 117, 1657–1658.

    Article  CAS  Google Scholar 

  45. G. Renger and Æ. T. Renger, The machinery of photosynthetic water splitting, Photosynth. Res., 2008, 98, 53.

    Article  CAS  PubMed  Google Scholar 

  46. K. Okamoto and S. Fukuzumi, Hydrogen Bonds Not Only Provide a Structural Scaffold to Assemble Donor and Acceptor Moieties of Zinc Porphyrin-Quinone Dyads but Also Control the Photoinduced Electron Transfer to Afford the Long-Lived Charge-Separated States, J. Phys. Chem. B, 2005, 109, 7713.

    Article  CAS  PubMed  Google Scholar 

  47. A. Cannizzo, F. Van Mourik, W. Gawelda, G. Zgrablic, C. Bressler and M. Chergui, Broadband Femtosecond Fluorescence Spectroscopy of [Ru(bpy)3]2+, Angew. Chem., Int. Ed., 2006, 45, 3174.

    Article  CAS  Google Scholar 

  48. Y. Kim, A. Das, H. Zhang and P. K. Dutta, Interfacial Electron Transfer Dynamics Involving a New Bis- Thiocyanate Ruthenium(II) Polypyridyl Complex, Coupled Strongly to Nanocrystalline TiO2, through a Pendant Catecholate Functionality, J. Phys. Chem. B, 2005, 109, 6929.

    Article  CAS  PubMed  Google Scholar 

  49. A. C. Bhasikuttan, M. Suzuki, S. Nakashima and T. Okada, Ultrafast Fluorescence Detection in Tris(2,2′-bipyridine) ruthenium(II) Complex in Solution: Relaxation Dynamics Involving Higher Excited States, J. Am. Chem. Soc., 2002, 124, 8398.

    Article  CAS  PubMed  Google Scholar 

  50. I. Loett and A. Trelnin, Photochemistry of 9,1O-Anthraquinone-2-sulfonate in Solution. 1. Intermediates and Mechanism, J. Phys. Chem., 1983, 87, 2536.

    Article  Google Scholar 

  51. A. D. Osborne and G. Porter, Primary Photochemical Processes in Aromatic Molecules, J. Chem. Soc., Faraday Trans., 1963, 60, 873.

    Google Scholar 

  52. M. Quan, D. Sanchez, M. F. Wasylkiw and D. K. Smith, Voltammetry of Quinones in Unbuffered Aqueous Solution: Reassessing the Roles of Proton Transfer and Hydrogen Bonding in the Aqueous Electrochemistry of Quinones, J. Am. Chem. Soc., 2007, 129, 12847.

    Article  CAS  PubMed  Google Scholar 

  53. C. Costentin, Electrochemical Approach to the Mechanistic Study of Proton-Coupled Electron Transfer, Chem. Rev., 2008, 108, 2145–2179.

    Article  CAS  PubMed  Google Scholar 

  54. K. P. Clark and H. I. Stonehill, Photochemistry and Radiation Chemistry of Anthraquinone-2-sodhm-sulphonate in Aqueous Solution, J. Chem. Soc., Faraday Trans., 1970, 68, 577.

    Article  Google Scholar 

  55. B. P. Sullivan, D. J. Salmon and T. J. Meyer, Mixed Phosphine 2,2′-Bipyridine Complexes of Ruthenium, Inorg. Chem., 1978, 17, 3334.

    Article  CAS  Google Scholar 

  56. S. Aute, P. Maity, A. Das and H. N. Ghosh, Demonstrating the role of anchoring functionality in interfacial electron transfer dynamics in the newly synthesized BODIPY–TiO2 nanostructure composite, New J. Chem., 2017, 5215–5224.

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Ananta Dey.

Additional information

Electronic supplementary information (ESI) available. See DOI: 10.1039/ c9pp00135b

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Dey, A., Dana, J., Aute, S. et al. Hydrogen bond assisted photoinduced intramolecular electron transfer and proton coupled electron transfer in an ultrafast time domain using a ruthenium-anthraquinone dyad†. Photochem Photobiol Sci 18, 2430–2441 (2019). https://doi.org/10.1039/c9pp00135b

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1039/c9pp00135b

Navigation