1
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Nielsen LG, Sørensen TJ. Effect of buffers and pH in antenna sensitized Eu(III) luminescence. Methods Appl Fluoresc 2023; 11. [PMID: 36696692 DOI: 10.1088/2050-6120/acb63a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/25/2023] [Indexed: 01/26/2023]
Abstract
The photophysics of a europium(III) complex of 1,4,7,10-tetraazacycododecane-1,4,7-triacetic acid-10-(2-methylene)-1-azathioxanthone was investigated in three buffer systems and at three pH values. The buffers-phosphate buffered saline (PBS), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), and universal buffer (UB)-had no effect on the europium luminescence, but a lower overall emission intensity was determined in HEPES. It was found that this was due to quenching of the 1-azathioxanthone first excited singlet state by HEPES. The effect of pH on the photophysics of the complex was found to be minimal, and protonation of the pyridine nitrogen was found to be irrelevant. Even so, pH was shown to change the intensity ratio between 1-azathioxanthone fluorescence and europium luminescence. It was concluded that the full photophysics of a potential molecular probe should be investigated to achieve the best possible results in any application.
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Affiliation(s)
- Lea Gundorff Nielsen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, København Ø, Denmark
| | - Thomas Just Sørensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, København Ø, Denmark
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2
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Wang L, Nawrocki P, Nielsen LG, Grenier L, Sørensen TJ. A europium(III)-based nanooptode for bicarbonate sensing - a multicomponent approach to sensor materials. Chem Commun (Camb) 2022; 58:9198-9201. [PMID: 35894692 DOI: 10.1039/d2cc02956a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lanthanide luminescence contains detailed chemical information and can be used to report on several chemical analytes. This has been exploited through elaborate synthesis of responsive lanthanide complexes. Here, we report on a less elaborate approach and assemble four different nanooptodes. Europium(III) is used to sense the bicarbonate concentration. The signal from the optode was enhanced 100 times using antenna chromophore and the response was modulated by the addition of lipophilic cations.
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Affiliation(s)
- Lu Wang
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
| | - Patrick Nawrocki
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
| | - Lea G Nielsen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
| | - Laura Grenier
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
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3
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Thomsen MS, Nawrocki PR, Kofod N, Sørensen TJ. Seven Europium(III) Complexes in Solution – the Importance of Reporting Data When Investigating Luminescence Spectra and Electronic Structure. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Maria S. Thomsen
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Patrick R. Nawrocki
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Nicolaj Kofod
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Thomas J. Sørensen
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
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4
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Abad Galán L, Hamon N, Nguyen C, Molnár E, Kiss J, Mendy J, Hadj-Kaddour K, Onofre M, Trencsényi G, Monnereau C, Beyler M, Tircsó G, Gary-Bobo M, Maury O, Tripier R. Design of polyazamacrocyclic Gd3+ theranostic agents combining magnetic resonance imaging and two-photon photodynamic therapy. Inorg Chem Front 2021. [DOI: 10.1039/d0qi01519a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
New “all-in-one” theranostic systems, combining a magnetic resonance imaging contrast agent with a biphotonic photodynamic therapy photosensitiser generating cytotoxic singlet oxygen, were successfully developed and characterized.
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5
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Dansholm CN, Junker AKR, Nielsen LG, Kofod N, Pal R, Sørensen TJ. π-Expanded Thioxanthones - Engineering the Triplet Level of Thioxanthone Sensitizers for Lanthanide-Based Luminescent Probes with Visible Excitation. Chempluschem 2020; 84:1778-1788. [PMID: 31943860 DOI: 10.1002/cplu.201900309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/12/2019] [Indexed: 12/17/2022]
Abstract
Bright lanthanide based probes for optical bioimaging must rely on the antenna principle, where the lanthanide-centred excited state is formed by a complex sensitization process. Efficient sensitization of lanthanide-centred emission occurs via triplet states centred on the sensitizing chromophore. Here, the triplet state of thioxanthone chromophores is modulated by extending the π-system. Three thioxanthone chromophores-thioxanthone, benzo[c]thioxanthone, and naphtho[2,3-c]thioxanthone were synthesised and characterised. The triplet state energies and lifetimes is found to change as expected, and two dyes are found to be suitable sensitizers for europium(iii) luminescence. Reactive derivatives of thioxanthone and benzo[c]thioxanthone were prepared and coupled to a 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A) lanthanide binding pocket. The photophysics and the performance in optical bioimaging of the resulting europium(iii) complexes were investigated. It is concluded that while the energetics favour efficient sensitization, the solution structure does not. While it was found that the complexes are too lipophilic to be efficient luminescent probes for optical bioimaging, we successfully demonstrated bioimaging using europium(iii) luminescence following 405 nm excitation.
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Affiliation(s)
- Charlotte Nybro Dansholm
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, København Ø, Denmark
| | - Anne Kathrine R Junker
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, København Ø, Denmark
| | - Lea G Nielsen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, København Ø, Denmark
| | - Nicolaj Kofod
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, København Ø, Denmark
| | - Robert Pal
- Department of Chemistry, Durham University Lower Mountjoy, Stockton Road, Durham DH1 3LE, UK
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, København Ø, Denmark
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6
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Galland M, Le Bahers T, Banyasz A, Lascoux N, Duperray A, Grichine A, Tripier R, Guyot Y, Maynadier M, Nguyen C, Gary‐Bobo M, Andraud C, Monnereau C, Maury O. A “Multi‐Heavy‐Atom” Approach toward Biphotonic Photosensitizers with Improved Singlet‐Oxygen Generation Properties. Chemistry 2019; 25:9026-9034. [DOI: 10.1002/chem.201901047] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/09/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Margaux Galland
- Laboratoire de Chimie de l'ENS de Lyon, Univ Lyon, ENS de Lyon, CNRS UMR 5182Université Claude Bernard Lyon 1 69342 Lyon France
| | - Tangui Le Bahers
- Laboratoire de Chimie de l'ENS de Lyon, Univ Lyon, ENS de Lyon, CNRS UMR 5182Université Claude Bernard Lyon 1 69342 Lyon France
| | - Akos Banyasz
- Laboratoire de Chimie de l'ENS de Lyon, Univ Lyon, ENS de Lyon, CNRS UMR 5182Université Claude Bernard Lyon 1 69342 Lyon France
| | - Noëlle Lascoux
- Laboratoire de Chimie de l'ENS de Lyon, Univ Lyon, ENS de Lyon, CNRS UMR 5182Université Claude Bernard Lyon 1 69342 Lyon France
| | - Alain Duperray
- INSERM, U1209Université Grenoble Alpes, IAB 38000 Grenoble France
| | - Alexei Grichine
- INSERM, U1209Université Grenoble Alpes, IAB 38000 Grenoble France
| | - Raphaël Tripier
- UFR des Sciences et TechniquesUniv Brest, UMR CNRS-UBO 6521 CEMCA, IBSAM 6 avenue Victor le Gorgeu, C.S. 93837 29238 Brest, Cedex 3 France
| | - Yannick Guyot
- Univ. LyonInstitut Lumière Matière, UMR 5306 CNRS-Université Claude Bernard Lyon 1 10 rue Ada Byron 69622 Villeurbanne Cedex France
| | | | - Christophe Nguyen
- Faculté de PharmacieInstitut de Biomolécules Max Mousseron, UMR 5247 CNRS-UM 15 Avenue Charles Flahault 34093 Montpellier Cedex 05 France
| | - Magali Gary‐Bobo
- Faculté de PharmacieInstitut de Biomolécules Max Mousseron, UMR 5247 CNRS-UM 15 Avenue Charles Flahault 34093 Montpellier Cedex 05 France
| | - Chantal Andraud
- Laboratoire de Chimie de l'ENS de Lyon, Univ Lyon, ENS de Lyon, CNRS UMR 5182Université Claude Bernard Lyon 1 69342 Lyon France
| | - Cyrille Monnereau
- Laboratoire de Chimie de l'ENS de Lyon, Univ Lyon, ENS de Lyon, CNRS UMR 5182Université Claude Bernard Lyon 1 69342 Lyon France
| | - Olivier Maury
- Laboratoire de Chimie de l'ENS de Lyon, Univ Lyon, ENS de Lyon, CNRS UMR 5182Université Claude Bernard Lyon 1 69342 Lyon France
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7
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Junker AKR, Sørensen TJ. Illuminating the Intermolecular vs. Intramolecular Excited State Energy Transfer Quenching by Europium(III) Ions. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Anne Kathrine R. Junker
- Nano‐Science Center & Department of Chemistry University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Thomas Just Sørensen
- Nano‐Science Center & Department of Chemistry University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
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8
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Junker AKR, Sørensen TJ. Shining light on the excited state energy cascade in kinetically inert Ln(iii) complexes of a coumarin-appended DO3A ligand. Dalton Trans 2019; 48:964-970. [DOI: 10.1039/c8dt04464c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Lanthanide based molecular probes for bioimaging relies on the antenna effect, here we are unravelling the excited state energy cascade that results in sensitized lanthanide luminescence.
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Affiliation(s)
- Anne Kathrine R. Junker
- Nano-Science Center & Department of Chemistry
- University of Copenhagen
- 2100 København Ø
- Denmark
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry
- University of Copenhagen
- 2100 København Ø
- Denmark
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9
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Galland M, Riobé F, Ouyang J, Saleh N, Pointillart F, Dorcet V, Le Guennic B, Cador O, Crassous J, Andraud C, Monnereau C, Maury O. Helicenic Complexes of Lanthanides: Influence of the f-Element on the Intersystem Crossing Efficiency and Competition between Luminescence and Oxygen Sensitization. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800922] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Margaux Galland
- Université Lyon; ENS de Lyon; CNRS UMR 5182; Laboratoire de Chimie; Université Claude Bernard Lyon 1 69342 Lyon France
| | - François Riobé
- Université Lyon; ENS de Lyon; CNRS UMR 5182; Laboratoire de Chimie; Université Claude Bernard Lyon 1 69342 Lyon France
| | - Jiangkun Ouyang
- Univ Rennes; CNRS; ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226; 35000 Rennes France
| | - Nidal Saleh
- Univ Rennes; CNRS; ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226; 35000 Rennes France
| | - Fabrice Pointillart
- Univ Rennes; CNRS; ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226; 35000 Rennes France
| | - Vincent Dorcet
- Univ Rennes; CNRS; ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226; 35000 Rennes France
| | - Boris Le Guennic
- Univ Rennes; CNRS; ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226; 35000 Rennes France
| | - Olivier Cador
- Univ Rennes; CNRS; ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226; 35000 Rennes France
| | - Jeanne Crassous
- Univ Rennes; CNRS; ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226; 35000 Rennes France
| | - Chantal Andraud
- Université Lyon; ENS de Lyon; CNRS UMR 5182; Laboratoire de Chimie; Université Claude Bernard Lyon 1 69342 Lyon France
| | - Cyrille Monnereau
- Université Lyon; ENS de Lyon; CNRS UMR 5182; Laboratoire de Chimie; Université Claude Bernard Lyon 1 69342 Lyon France
| | - Olivier Maury
- Université Lyon; ENS de Lyon; CNRS UMR 5182; Laboratoire de Chimie; Université Claude Bernard Lyon 1 69342 Lyon France
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10
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Galimov DI, Yakupova SM, Bulgakov RG. Divalent Eu 2+ ion - an effective inorganic mediator of energy transfer from the primary chemiluminescence emitter 3 Me 2 CHC(H)=O* on Tb 3+ and Ru(bpy) 3 2+ ions. LUMINESCENCE 2018; 33:1365-1370. [PMID: 30318859 DOI: 10.1002/bio.3554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/30/2018] [Accepted: 09/01/2018] [Indexed: 01/26/2023]
Abstract
This study demonstrated for the first time that chemiluminescence (CL) from oxidation of Bui 2 AlH (Bu = C4 H9 ) using oxygen from tetrahydrofuran (THF) was significantly enhanced by the addition of Ru(bpy)3 2+ . A quantitative comparison of the enhancement efficiency of this CL was performed by addition of ionic phosphors Eu2+ , Tb3+ and Ru(bpy)3 2+ . CL enhancement was caused by energy transfer from the primary CL emitter (3 Me2 CHC(H)=O* aldehyde) to these ionic phosphors. The CL efficiency enhancement was in the order: Eu2+ (8.9 × 106 ) > Tb3+ (100) > Ru(bpy)3 2+ (50). The enhanced CL emitters were excited ions: Eu2+ *, λmax = 465 nm; Tb3+ *, λmax = 485, 542, 625 nm; and Ru(bpy)3 2+ *, λmax = 567 nm. When two ions Eu2+ -Tb3+ or Eu2+ -Ru(bpy)3 2+ were present in the reaction solution, the efficiency of CL enhancement by Tb3+ or Ru(bpy)3 2+ ions was much higher, being 1.2 × 106 and 4.2 × 104 , respectively. In this case, two excited ions were simultaneously registered as CL emitters: Eu2+ * and Tb3+ * or Eu2+ * and Ru(bpy)3 2+ *. Emission intensity of the Eu2+ * ion in these emitter doublets is much lower than when only one Eu2+ ion is present in solution.
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Affiliation(s)
- D I Galimov
- Institute of Petrochemistry and Catalysis, Ufa Federal Research Center of the Russian Academy of Sciences, 141 Prospect Oktyabrya, Ufa, Russia
| | - S M Yakupova
- Institute of Petrochemistry and Catalysis, Ufa Federal Research Center of the Russian Academy of Sciences, 141 Prospect Oktyabrya, Ufa, Russia
| | - R G Bulgakov
- Institute of Molecule and Crystal Physics Ufa Federal Research Center of the Russian Academy of Sciences, 71 Prospect Oktyabrya, Ufa, Russia
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11
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Arppe‐Tabbara R, Carro‐Temboury MR, Hempel C, Vosch T, Sørensen TJ. Luminescence from Lanthanide(III) Ions Bound to the Glycocalyx of Chinese Hamster Ovary Cells. Chemistry 2018; 24:11885-11889. [DOI: 10.1002/chem.201802799] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/25/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Riikka Arppe‐Tabbara
- Nano-Science Center & Department of ChemistryUniversity of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Miguel R. Carro‐Temboury
- Nano-Science Center & Department of ChemistryUniversity of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Casper Hempel
- Department of Micro- and NanotechnologyTechnical University of Denmark Kgs Lyngby Denmark
| | - Tom Vosch
- Nano-Science Center & Department of ChemistryUniversity of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Thomas Just Sørensen
- Nano-Science Center & Department of ChemistryUniversity of Copenhagen Universitetsparken 5 2100 København Ø Denmark
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12
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Junker AKR, Hill LR, Thompson AL, Faulkner S, Sørensen TJ. Shining light on the antenna chromophore in lanthanide based dyes. Dalton Trans 2018; 47:4794-4803. [PMID: 29560975 DOI: 10.1039/c7dt04788f] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Lanthanide based dyes and assays exploit the antenna effect, where a sensitiser-chromophore is used as a light harvesting antenna and subsequent excited state energy transfer populates the emitting lanthanide centred excited state. A rudimentary understanding of the design criteria for designing efficient dyes and assays based on the antenna effect is in place. By preparing kinetically inert lanthanide complexes based on the DO3A scaffold, we are able to study the excited state energy transfer from a 7-methoxy-coumarin antenna chromophore to europium(iii) and terbium(iii) centred excited states. By contrasting the photophysical properties of complexes of metal centres with and without accessible excited states, we are able to separate the contributions from the heavy atom effect, photoinduced electron transfer quenching, excited state energy transfer and molecular conformations. Furthermore, by studying the photophysical properties of the antenna chromophore, we can directly monitor the solution structure and are able to conclude that excited state energy transfer from the chromophore singlet state to the lanthanide centre does occur.
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Affiliation(s)
- Anne Kathrine R Junker
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Leila R Hill
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
| | - Amber L Thompson
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
| | - Stephen Faulkner
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
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13
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Junker AKR, Deblonde GJP, Abergel RJ, Sørensen TJ. Investigating subtle 4f vs. 5f coordination differences using kinetically inert Eu(iii), Tb(iii), and Cm(iii) complexes of a coumarin-appended 1,4,7,10-tetraazacyclododecane-1,4,7-triacetate (DO3A) ligand. Dalton Trans 2018; 47:7362-7369. [DOI: 10.1039/c8dt01547c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Coumarin appended DO3A complexes of Cm(iii), Eu(iii), and Tb(iii) show that more than ionic radius determines the coordination chemistry of the f-elements.
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Affiliation(s)
- Anne Kathrine R. Junker
- Nano-Science Center & Department of Chemistry
- University of Copenhagen
- 2100 København Ø
- Denmark
| | | | - Rebecca J. Abergel
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Nuclear Engineering
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry
- University of Copenhagen
- 2100 København Ø
- Denmark
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14
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Junker AKR, Sørensen TJ. Rationalizing substituent effects in 1-azathioxanthone photophysics. Methods Appl Fluoresc 2017; 6:014002. [PMID: 29160773 DOI: 10.1088/2050-6120/aa9c16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The influence of an electron donating substituent on the photophysical properties of 1-azathioxanthone dyes has been investigated using optical spectroscopy and theoretical models. The motivation behind the study is based on the fact that thioxanthones are efficient triplet sensitizers, and thus promising sensitizers for lanthanide centered emission. By adding an aza group to one of the phenyl ring systems, direct coordination to a lanthanide center becomes possible, which makes azathoixanthones great candidates as antenna chromophores in lanthanide(III) based dyes. Here, three 1-azathioxanthone derivatives have been synthesized targeting efficient triplet formation following absorption in the visible range of the spectrum. This is achieved by adding methoxy groups to the 1-azathioxanthone core. The derivatives were characterized using absorption, emission, and time-gated emission spectroscopy, where fluorescent quantum yields, singlet and triplet excited states lifetimes were determined. The experimentally determined photophysical properties of the three 1-azathioxanthone compounds are contrasted to those of the parent thioxanthone and is rationalized using the Strickler-Berg equation, Hückel MO theory, and Dewar's rules in combination with computational chemistry. We find that the transition energies follow predictions, but that the overall photophysical properties are determined by the relative energies as well as the nature of the involved states in both the singlet and the triplet excited state manifolds.
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Affiliation(s)
- Anne Kathrine R Junker
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 København Ø, Denmark
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