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Generation of reactive oxygen species by photolysis of the ruthenium(ii) complex Ru(NH3)5(pyrazine)2+ in oxygenated solution

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Abstract

Metal-to-ligand charge transfer photolysis of the ruthenium(ii) pyrazine complex Ru(NH3)5pz2+ (I) in pH 7.4 oxygenated phosphate buffer solution generates the Ru(iii) analog Ru(NH3)5pz3+ plus the reactive oxygen species singlet oxygen and superoxide. Based on the very short MLCT lifetime (re-measured as ~250 ps in D2O) of I* and the quantum yield for singlet oxygen formation (0.01 for aerated D2O) the rate constant for oxygen quenching ofI* was calculated to be ~(3 ± 1) × 1010 M-1 s-1.

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Authors and Affiliations

  1. Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n, CEP 14040-903, Ribeirão Preto, SP, Brazil

    Roberto Santana da Silva & Mario Sergio P. Marchesi

  2. Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA, 93106-9510, USA

    Roberto Santana da Silva, Alexander Mikhailovsky & Peter C. Ford

  3. Departamento de Química da Faculdade de Filosofia Ciencias e Letras de Ribeirão Preto, Av. dos Bandeirantes s/n, CEP 14040-903, Ribeirão Preto, SP, Brazil

    Roberto Santana da Silva & Antonio Claudio Tedesco

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  1. Roberto Santana da Silva
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  2. Mario Sergio P. Marchesi
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  3. Antonio Claudio Tedesco
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  4. Alexander Mikhailovsky
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  5. Peter C. Ford
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Correspondence to Roberto Santana da Silva.

Additional information

Electronic supplementary information (ESI) available: Fig. S1 showing changes in TEMPO EPR spectrum.

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da Silva, R.S., Marchesi, M.S.P., Tedesco, A.C. et al. Generation of reactive oxygen species by photolysis of the ruthenium(ii) complex Ru(NH3)5(pyrazine)2+ in oxygenated solution. Photochem Photobiol Sci 6, 515–518 (2007). https://doi.org/10.1039/b617350k

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  • DOI: https://doi.org/10.1039/b617350k

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