fulltext.study @t Gmail

Theoretical assessment of the photosensitization mechanisms of porphyrin–ruthenium(II) complexes for the formation of reactive oxygen species

Paper ID Volume ID Publish Year Pages File Format Full-Text
26138 43936 2014 7 PDF Available
Title
Theoretical assessment of the photosensitization mechanisms of porphyrin–ruthenium(II) complexes for the formation of reactive oxygen species
Abstract

•We propose photosensitization mechanisms for the formation of reactive oxygen species.•Energy-transfer and electron-transfer processes were assessed.•Generation of 1O2 is favored for Ru(II) complexes in their triplet excited state.•Anionic radical of porphyrin–Ru(II) complex favors the formation of the superoxide anion radical.

Following a thermodynamics point of view, we analyzed a set of photosensitization mechanisms (energy transfer, electron transfer) given by seven reactions applied to porphyrin–ruthenium(II) complexes (1–6) and their fragments (ruthenium complexes: 7–12; porphyrin: 13) at the B3LYP/6–31G(d,p)/LANL2DZ level of theory in condensed phase (aqueous solution). We found that whereas for the fragments (7–13) an energy-transfer process between their first triplet excited state (T1) and molecular oxygen (3O2) to yield singlet oxygen (1O2) is favored, the privileged channels for the photosensitizers (1–6) correspond to production of a superoxide anion radical (O2−) by electron transfer between 3O2 and the photosensitizers (P) either in their P(T1) excited state or as a radical anion P−. The reaction channels involving P− are more exergonic by 13–17 kcal/mol with respect to the process involving P(T1). These results suggest that the anionic photosensitizer would likely acquire more importance for the photodamage in the cell.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Photosensitization; Electron transfer; Energy transfer; Porphyrin; Ruthenium; Reactive oxygen species
First Page Preview
Theoretical assessment of the photosensitization mechanisms of porphyrin–ruthenium(II) complexes for the formation of reactive oxygen species
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 294, 15 November 2014, Pages 68–74
Authors
, , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us