Photo-induced electron transfer in a diamino-substituted Ru(bpy)3 [PF6]2 complex and its application as a triplet photosensitizer for nitric oxide (NO)-activated triplet-triplet annihilation upconversion

Xu, Kejing, Zhao, Jianzhang and Moore, Evan G. (2016) Photo-induced electron transfer in a diamino-substituted Ru(bpy)3 [PF6]2 complex and its application as a triplet photosensitizer for nitric oxide (NO)-activated triplet-triplet annihilation upconversion. Photochemical and Photobiological Sciences, 15 8: 995-1005. doi:10.1039/C6PP00153J


Author Xu, Kejing
Zhao, Jianzhang
Moore, Evan G.
Title Photo-induced electron transfer in a diamino-substituted Ru(bpy)3 [PF6]2 complex and its application as a triplet photosensitizer for nitric oxide (NO)-activated triplet-triplet annihilation upconversion
Formatted title
Photo-induced electron transfer in a diamino-substituted Ru(bpy)3 [PF6]2 complex and its application as a triplet photosensitizer for nitric oxide (NO)-activated triplet-triplet annihilation upconversion
Journal name Photochemical and Photobiological Sciences   Check publisher's open access policy
ISSN 1474-905X
1474-9092
Publication date 2016
Year available 2016
Sub-type Article (original research)
DOI 10.1039/C6PP00153J
Open Access Status Not Open Access
Volume 15
Issue 8
Start page 995
End page 1005
Total pages 11
Place of publication Cambridge, United Kingdom
Publisher Royal Society of Chemistry
Collection year 2017
Language eng
Formatted abstract
A system demonstrating Nitric Oxide (NO) activated Triplet–Triplet Annihilation (TTA) upconversion has been devised, based on a substituted [RuII(bpy)3](PF6)2 complex (bpy = 2,2′-dipyridine) bearing a single 1,2-diaminophenyl moiety as an NO activatable triplet photosensitizer (Ru-1), and 9,10-diphenylanthracene (DPA) as a triplet acceptor/emitter. The excited triplet state of Ru-1 is significantly quenched (ΦT ∼ 22%) by a Photoinduced Electron Transfer (PET) reaction, as confirmed by steady state phosphorescence and transient absorption spectroscopy, and hence Ru-1 does not function as a TTA upconversion sensitizer. However, in the presence of NO/O2, the 1,2-diaminophenyl group of Ru-1 is transformed into a benzotriazole. This inhibits PET, and the triplet state quantum yield is increased to ca. 85%, switching on the TTA upconversion process which increases by 10-fold. These processes were studied using a combination of steady state and time-resolved luminescence together with transient absorption spectroscopy on the nanosecond and femtosecond timescales. The energy level of the charge transfer state (CTS) for Ru-1 was also obtained electrochemically, supporting the PET mechanism of triplet state quenching and hence the lack of TTA upconversion with Ru-1.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
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School of Chemistry and Molecular Biosciences
 
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Created: Fri, 15 Jul 2016, 12:08:57 EST by Mrs Louise Nimwegen on behalf of School of Chemistry & Molecular Biosciences