uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Photophysics of Coumarin and Carbostyril-Sensitized Luminescent Lanthanide Complexes: Implications for Complex Design in Multiplex Detection
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
Show others and affiliations
2017 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 139, no 16, p. 5756-5767Article in journal (Refereed) Published
Abstract [en]

Luminescent lanthanide (Ln(III)) complexes with coumarin or carbostyril antennae were synthesized and their photophysical properties evaluated using steady-state and time-resolved UV-vis spectroscopy. Ligands bearing distant hydroxycoumarin-derived antennae attached through triazole linkers were modest sensitizers for Eu(III) and Tb(III), whereas ligands with 7-amidocarbostyrils directly linked to the coordination site could reach good quantum yields for multiple Ln(III), including the visible emitters Sm(III) and Dy(III), and the near-infrared emitters Nd(III) and Yb(III). The highest lanthanide-centered luminescence quantum yields were 35% (Tb), 7.9% (Eu), 0.67% (Dy), and 0.18% (Sm). Antennae providing similar luminescence intensities with 2-4 Ln-emitters were identified. Photoredox quenching of the carbostyril antenna excited states was observed for all Eu(III)-complexes and should be sensitizing in the case of Yb(III); the scope of the process extends to Ln(III) for which it has not been seen previously, specifically Dy(III) and Sm(III). The proposed process is supported by photophysical and electrochemical data. A FRET-type mechanism was identified in architectures with both distant and close antennae for all of the Lns. This mechanism seems to be the only sensitizing one at long distance and probably contributes to the sensitization at shorter distances along with the triplet pathway. The complexes were nontoxic to either bacterial or mammalian cells. Complexes of an ester-functionalized ligand were taken up by bacteria in a concentration-dependent manner. Our results suggest that the effects of FRET and photoredox quenching should be taken into consideration when designing luminescent Ln complexes. These results also establish these Ln(III)-complexes for multiplex detection beyond the available two-color systems.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC , 2017. Vol. 139, no 16, p. 5756-5767
National Category
Chemical Sciences Engineering and Technology
Identifiers
URN: urn:nbn:se:uu:diva-322722DOI: 10.1021/jacs.6b11274ISI: 000400321500029PubMedID: 28388066OAI: oai:DiVA.org:uu-322722DiVA, id: diva2:1099137
Funder
Swedish Research Council, 2013-4655Stiftelsen Olle Engkvist ByggmästareAvailable from: 2017-05-29 Created: 2017-05-29 Last updated: 2019-04-16Bibliographically approved
In thesis
1. Photoinduced Electron Transfer in Luminescent Lanthanide Complexes
Open this publication in new window or tab >>Photoinduced Electron Transfer in Luminescent Lanthanide Complexes
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Luminescence from the trivalent lanthanides is used for detection in biological systems. Lanthanide luminescence is usually sensitized by a light-harvesting organic chromophore (’antenna’). An ideal emitter has an antenna that efficiently transfers energy to the lanthanide, and a ligand that shields the metal from quenching solvent molecules.

Additional photophysical processes can impact the luminescence quantum yield. One such process is electron transfer from the excited state antenna to the lanthanide, yielding a lanthanide(II) and an antenna radical cation. Back electron transfer returns the antenna and a lanthanide(III), which, may or may not emit a photon.

This thesis summarizes my work on the investigation of the photoinduced electron transfer in lanthanide complexes. Chapter 1 is a brief introduction. Chapter 2 describes a structure-activity relationship in a focused library of lanthanide complexes. PeT was observed with most antennae and in a larger of lanthanides than previously assumed.

In Chapter 3, the role of the linker connecting the antenna and the metal binding site is investigated. Replacement of the secondary amide linker with a tertiary amide yielded unexpectedly high luminescence quantum yields. This was attributed to an improved sensitization efficiency due to a combination of factors (structural as well as electronic) in the Eu complexes, and a reduced back energy transfer in the Tb complexes.

In Chapter 4, the role of the ligand in PeT was investigated. Stabilization of the lanthanide(III) state by encapsulation of the ion in a highly negatively charged ligand resulted in a recovery of some of the excitation energy lost to PeT. The addition of external a strongly coordinating anionic ligand, fluoride, which could replace the charge-neutral water ligand, had a similar effect. The changes in the lanthanide redox potential was confirmed by cyclic voltammetry.

Finally, complexes equipped with azide and alkyne reactive handles are described. The introduction of bioconjugatable groups had only a small effect on the luminescent properties of the compounds. We attempted to improve the luminescence quantum yields by excluding the lanthanide-bound water molecule that has been occupying the ninth coordination. However, the nonadentate ligands did not yield appreciably better emitters due to a carbostyril-to-pyridine PeT.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2019. p. 99
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1809
Keywords
Lanthanide, Luminescence, Photoinduced electron transfer
National Category
Inorganic Chemistry
Research subject
Chemistry
Identifiers
urn:nbn:se:uu:diva-381905 (URN)978-91-513-0657-5 (ISBN)
Public defence
2019-06-10, Häggsalen, 10132, Ångstömlaboratoriet, Lägerhyddsvägen 1, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2019-05-20 Created: 2019-04-16 Last updated: 2019-06-17

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMed

Authority records BETA

Kovacs, DanielMeszaros, Livia S.Ott, MarjamBorbas, K. Eszter

Search in DiVA

By author/editor
Kovacs, DanielLu, XiMeszaros, Livia S.Ott, MarjamBorbas, K. Eszter
By organisation
Molecular BiomimeticsApplied Materials Sciences
In the same journal
Journal of the American Chemical Society
Chemical SciencesEngineering and Technology

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 607 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf