Abstract
The excited-state quenching of [Ru(TAP)2(HAT)]2+ (TAP = 1,4,5,8-tetraazaphenanthrene, HAT= 1,4,5,8,9,12-hexaazatriphenylene) by hydroquinone (H2Q), N-acetyl-tyrosine (N-Ac-Tyr) or guanosine-5′-monophosphate (GMP) was investigated at various pH values. The quenching occurs via electron/proton transfer, as evidenced by transient absorption spectroscopy and confirmed by 1H photochemically induced dynamic nuclear polarization (photo-CIDNP). Reductive quenching also occurs in strongly acidic solution despite a much shorter lifetime of the protonated excited-state complex. Photo-CIDNP revealed a different mechanism at low pH, involving protonation before electron transfer and yielding a distinct protonated monoreduced complex. The experimental photo-CIDNP patterns are consistent with density functional theory calculations. This work highlights the power of 1H photo-CIDNP for characterizing, at the atomic level, transient species involved in electron-transfer processes.
Original language | English |
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Pages (from-to) | 14909-14912 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 139 |
Issue number | 42 |
DOIs | |
Publication status | Published - 25 Oct 2017 |
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Physical Chemistry and characterization(PC2)
Wouters, J. (Manager), Aprile, C. (Manager) & Fusaro, L. (Manager)
Technological Platform Physical Chemistry and characterizationFacility/equipment: Technological Platform