1
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Simms CH, Nielsen VRM, Sørensen TJ, Faulkner S, Langton MJ. Photoswitchable luminescent lanthanide complexes controlled and interrogated by four orthogonal wavelengths of light. Phys Chem Chem Phys 2024; 26:18683-18691. [PMID: 38922672 DOI: 10.1039/d4cp02243b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Optical information storage requires careful control of excitation and emission wavelengths in a reversible and orthogonal manner to enable efficient reading, writing, and erasing of information. Photochromic systems, in which a photoswitch is typcially coupled to an emissive organic fluorophore, have much promise in this regard. However, these suffer from considerable spectral overlap between the switch and fluorophore, such that their emissive and photoswitchable properties are not orthogonal. Here, we overcome this limitation by coupling visible/NIR emissive lanthanide complexes with molecular photoswitches, enabling reversible and orthogonal photoswitching with visible light. Crucially, photoswitching does not lead to sensitised emission from the lanthanide, while excitation of the lanthanide does not induce photoswitching, enabling the state of the system to be probed without perturbation of the switch. This opens up the possibility of developing multi-colour read-write methods for information storage using emissive photoswitches.
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Affiliation(s)
- Charlie H Simms
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, Mansfield road, Oxford, OX1 3TA, UK.
| | - Villads R M Nielsen
- Nano-Science Centre and Department of Chemistry University of Copenhagen Universitetsparken 5, 2100 København Ø, Denmark
| | - Thomas Just Sørensen
- Nano-Science Centre and Department of Chemistry University of Copenhagen Universitetsparken 5, 2100 København Ø, Denmark
| | - Stephen Faulkner
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, Mansfield road, Oxford, OX1 3TA, UK.
| | - Matthew J Langton
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, Mansfield road, Oxford, OX1 3TA, UK.
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2
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Kofod N, Sørensen TJ. Step-wise changes in the excited state lifetime of [Eu(D 2O) 9] 3+ and [Eu(DOTA)(D 2O)] - as a function of the number of inner-sphere O-H oscillators. Dalton Trans 2024; 53:9741-9749. [PMID: 38780119 DOI: 10.1039/d4dt00744a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Lanthanide luminescence is dominated by quenching by high-energy oscillators in the chemical environment. The rate of non-radiative energy transfer to a single H2O molecule coordinated to a Eu3+ ion exceeds the usual rates of emission by an order of magnitude. We know these rates, but the details of these energy transfer processes are yet to be established. In this work, we study the quenching rates of [Eu(D2O)9]3+ and [Eu(DOTA)(D2O)]- in H2O/D2O mixtures by sequentially exchanging the deuterons with protons. Flash freezing the solutions allows us to identify species with various D/H contents in solution and thus to quantify the energy transfer processes to individual OH-oscillators. This is not possible in solution due to fast exchange in the ensembles present at room temperature. We conclude that the energy transfer processes are accurately described, predicted, and simulated using a step-wise addition of the rates of quenching by each O-H oscillator. This documents the sequential increase in the rate of the energy transfer processes in the quenching of lanthanide luminescence, and further provides a methodology to identify isotopic impurities in deuterated lanthanide systems in solution.
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Affiliation(s)
- Nicolaj Kofod
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M9 13PL, UK.
- Department of Chemistry and Nano-Science Centre, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Thomas Just Sørensen
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M9 13PL, UK.
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3
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Nielsen LG, Andersen HOB, Kenwright AM, Platas-Iglesias C, So Rensen TJ. Using Chiral Auxiliaries to Mimic the Effect of Chiral Media on the Structure of Lanthanide(III) Complexes Common in Bioimaging and Diagnostic MRI. Inorg Chem 2024; 63:7560-7570. [PMID: 38610098 DOI: 10.1021/acs.inorgchem.3c01589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
[Ln·DOTA]- complexes and systems derived therefrom are commonly used in MRI and optical bioimaging. These lanthanide(III) complexes are chiral, and, in solution, they are present in four forms, with two sets of enantiomers, with the ligand donors arranged in either a square antiprismatic, SAP, or twisted square antiprismatic geometry, TSAP. This complicated speciation is found in laboratory samples. To investigate speciation in biological media, when Ln·DOTA-like complexes interact with chiral biomolecules, six Eu·DOTA-monoamide complexes were prepared and investigated by using 1D and 2D 1H NMR. To emulate the chirality of biological media, the amide pendant arm was modified with one or two chiral centers. It is known that a chiral center on the DOTA scaffold significantly influences the properties of the system. Here, it was found that chirality much further away from the metal center changes the available conformational space and that both chiral centers and amide cis/trans isomerism may need to be considered─a fact that, for the optically enriched materials, led to the conclusion that eight chemically different forms may need to be considered, instead of the four forms necessary for DOTA. The results reported here clearly demonstrate the diverse speciation that must be considered when correlating an observation to a structure of a lanthanide(III) complex.
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Affiliation(s)
- Lea Gundorff Nielsen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, Ko̷benhavn Ø DK2100, Denmark
| | - Helene O B Andersen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, Ko̷benhavn Ø DK2100, Denmark
| | - Alan M Kenwright
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Carlos Platas-Iglesias
- Centro Interdisciplinar de Química e Bioloxía (CICA) and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña, Galicia 15071, Spain
| | - Thomas Just So Rensen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, Ko̷benhavn Ø DK2100, Denmark
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4
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Kofod N, Henrichsen MJ, Sørensen TJ. Mapping the distribution of electronic states within the 5D 4 and 7F 6 levels of Tb 3+ complexes with optical spectroscopy. Dalton Trans 2024; 53:4461-4470. [PMID: 38372338 DOI: 10.1039/d3dt03657j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
The Tb(III) ion has the most intense luminescence of the trivalent lanthanide(III) ions. In contrast to Eu(III), where the two levels only include a single state, the high number of electronic states in the ground (7F6) and emitting (5D4) levels makes detailed interpretations of the electronic structure-the crystal field-difficult. Here, luminescence emission and excitation spectra of Tb(III) complexes with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA, [Tb(DOTA)(H2O)]-), ethylenediaminetetraacetic acid (EDTA, [Tb(EDTA)(H2O)3]-) and diethylenetriaminepentaacetic acid (DTPA, [Tb(DTPA)(H2O)]2-) as well as the Tb(III) aqua ion ([Tb(H2O)9]3+) were recorded at room temperature and in frozen solution. Using these data the electronic structure of the 5D4 multiplets of Tb(III) was mapped by considering the transitions to the singly degenerate 7F0 state. A detailed spectroscopic investigation was performed and it was found that the 5D4 multiplet could accurately be described as a single band for [Tb(H2O)9]3+, [Tb(DOTA)(H2O)]- and [Tb(EDTA)(H2O)3]-. In contrast, for [Tb(DTPA)(H2O)]2- two bands were needed. These results demonstrated the ability of describing the electronic structure of the emitting 5D4 multiplet using emission spectra. This offers an avenue for investigating the relationship between molecular structure and luminescent properties in detailed photophysical studies of Tb(III) ion complexes.
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Affiliation(s)
- Nicolaj Kofod
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Margrete Juel Henrichsen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Thomas Just Sørensen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
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5
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Thornton ME, Hemsworth J, Hay S, Parkinson P, Faulkner S, Natrajan LS. Heterometallic lanthanide complexes with site-specific binding that enable simultaneous visible and NIR-emission. Front Chem 2023; 11:1232690. [PMID: 37583568 PMCID: PMC10424921 DOI: 10.3389/fchem.2023.1232690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/17/2023] [Indexed: 08/17/2023] Open
Abstract
Macrocyclic lanthanide complexes have become widely developed due to their distinctive luminescence characteristics and wide range of applications in biological imaging. However, systems with sufficient brightness and metal selectivity can be difficult to produce on a molecular scale. Presented herein is the stepwise introduction of differing lanthanide ions in a bis-DO3A/DTPA scaffold to afford three trinuclear bimetallic [Ln2Ln'] lanthanide complexes with site-specific, controlled binding [(Yb2Tb), (Eu2Tb), (Yb2Eu)]. The complexes display simultaneous emission from all LnIII centers across the visible (TbIII, EuIII) and near infra-red (YbIII) spectrum when excited via phenyl ligand sensitization at a wide range of temperatures and are consequently of interest for exploiting imaging in the near infra-red II biological window. Analysis of lifetime data over a range of excitation regimes reveals intermetallic communication between TbIII and EuIII centers and further develops the understanding of multimetallic lanthanide complexes.
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Affiliation(s)
- Matthew E. Thornton
- Department of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester, United Kingdom
| | - Jake Hemsworth
- Department of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester, United Kingdom
| | - Sam Hay
- Department of Chemistry, Faculty of Science and Engineering, Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Patrick Parkinson
- Department of Physics and Astronomy and the Photon Science Institute, Faculty of Science and Engineering, The University of Manchester, Manchester, United Kingdom
| | - Stephen Faulkner
- Department of Chemistry, Chemistry Research Laboratory, The University of Oxford, Oxford, United Kingdom
| | - Louise S. Natrajan
- Department of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester, United Kingdom
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6
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Nielsen VRM, Nawrocki PR, Sørensen TJ. Electronic Structure of Neodymium(III) and Europium(III) Resolved in Solution Using High-Resolution Optical Spectroscopy and Population Analysis. J Phys Chem A 2023; 127:3577-3590. [PMID: 37053513 DOI: 10.1021/acs.jpca.3c00233] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Solution chemistry of the lanthanide(III) ions is unexplored and relevant: extraction and recycling processes exclusively operate in solution, MRI is a solution-phase method, and bioassays are done in solution. However, the molecular structure of the lanthanide(III) ions in solution is poorly described, especially for the near-IR (NIR)-emitting lanthanides, as these are difficult to investigate using optical tools, which has limited the availability of experimental data. Here we report a custom-built spectrometer dedicated to investigation of lanthanide(III) luminescence in the NIR region. Absorption, luminescence excitation, and luminescence spectra of five complexes of europium(III) and neodymium(III) were acquired. The obtained spectra display high spectral resolution and high signal-to-noise ratios. Using the high-quality data, a method for determining the electronic structure for the thermal ground states and emitting states is proposed. It combines Boltzmann distributions with population analysis and uses the experimentally determined relative transition probabilities from both excitation and emission data. The method was tested on the five europium(III) complexes and was used to resolve the electronic structures of the ground state and the emitting state of neodymium(III) in five different solution complexes. This is the first step toward correlating optical spectra with chemical structure in solution for NIR-emitting lanthanide complexes.
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Affiliation(s)
- Villads R M Nielsen
- Department of Chemistry and Nano-Science Centre, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Patrick R Nawrocki
- Department of Chemistry and Nano-Science Centre, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Thomas Just Sørensen
- Department of Chemistry and Nano-Science Centre, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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7
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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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8
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Photonic properties and applications of multi-functional organo-lanthanide complexes: Recent advances. J RARE EARTH 2023. [DOI: 10.1016/j.jre.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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9
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Mathieu E, Kiraev SR, Kovacs D, Wells JAL, Tomar M, Andres J, Borbas KE. Sensitization Pathways in NIR-Emitting Yb(III) Complexes Bearing 0, +1, +2, or +3 Charges. J Am Chem Soc 2022; 144:21056-21067. [DOI: 10.1021/jacs.2c05813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Emilie Mathieu
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Salauat R. Kiraev
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Daniel Kovacs
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Jordann A. L. Wells
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Monika Tomar
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Julien Andres
- Chemistry and Chemical Engineering Section, Ecole Polytechnique Fédérale de Lausanne (EPFL), BCH 3311, CH-1015 Lausanne, Switzerland
| | - K. Eszter Borbas
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
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10
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Storm Thomsen M, Andersen HOB, Sørensen TJ. Long story short: donor set symmetry in [Eu(DOTA)(H 2O)] - crystals determines the electronic structure. Dalton Trans 2022; 51:14118-14124. [PMID: 36043508 DOI: 10.1039/d2dt02172b] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lanthanide complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid DOTA have been studied in great detail due to their use as MRI contrast agents. Since the first report from Desreux in 1980, the Ln[DOTA]- complexes of gadolinium(III) in particular have been thoroughly investigated. The forms of the nine-coordinated [Ln(DOTA)(H2O)]- complexes are well known, and the ligand backbone has been used extensively to create functional MRI contrast agents, luminescent probes, and as a model system for studying the properties of lanthanide(III) ions. In solution, the photophysical properties have been mapped, but as the structures are not known, direct structure-property relationships have not been created. Here, the electronic properties of two Eu[DOTA] compounds (1 and 2) and a Eu[DOTA]-like compound (3) were studied using single-crystal luminescence spectroscopy. The donor set in the three compounds is identical (4N 4O 1O), and using the symmetry deviation value σideal it was shown that the coordination geometry is close to identical. Nevertheless, the electronic properties evaluated using the luminescence spectrum were found to differ significantly between the three compounds. The magnitude of the crystal field splitting was found not to scale with the symmetry of the coordination geometry. It was concluded that the donor set dictates the splitting, yet the structure-property relationships governing the electronic properties of europium(III) ions still elude us.
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Affiliation(s)
- Maria Storm Thomsen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
| | - Helene Obel Bøch Andersen
- 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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11
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Nawrocki PR, Nielsen VMR, Sørensen TJ. A high-sensitivity rapid acquisition spectrometer for lanthanide(III) luminescence. Methods Appl Fluoresc 2022; 10. [PMID: 36027890 DOI: 10.1088/2050-6120/ac8d4d] [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: 07/06/2022] [Accepted: 08/26/2022] [Indexed: 11/11/2022]
Abstract
Detecting luminescence beyond 750-800 nm becomes problematic as most conventional detectors are less sensitive in this range, and as simple corrections stops being accurate. Lanthanide luminescence occurs in narrow bands across the spectrum from 350-2000 nm. The most emissive lanthanide(III) ions have bands from 450 nm to 850 nm, some with additional bands in the NIR. Investigating the NIR bands are hard, but the difficulties start already at 700 nm. In general, the photon flux from lanthanide(III) emitters is not great, and the bands beyond 700 nm are very weak, we therefore decided to build a spectrometer based on cameras for microscopy with single-photon detection capabilities. This was found to allieviate all limitations and to allow for fast and efficient recording of luminescence spectra in the range from 450 to 950 nm. The spectrometer characteristics were investigated and the performance was benchmarked against two commercial spectrometers. We conclude that this spectrometer is ideal for investigating lanthanide luminescence, an all other emitters with emission in the target range.
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Affiliation(s)
- Patrick R Nawrocki
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, København Ø, 2100, DENMARK
| | - Villads M R Nielsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, København Ø, 2100, DENMARK
| | - Thomas Just Sørensen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, København Ø, 2100, DENMARK
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12
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Holzapfel M, Baldau T, Kerpa S, Guadalupi G, Qi B, Liu Y, Parak WJ, Maison W. Solution Structure and Relaxivity of Ln‐DOTXAZA Derivatives. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Malte Holzapfel
- Fraunhofer Institute for Applied Polymer Research: Fraunhofer-Institut fur Angewandte Polymerforschung IAP Center for Applied Nanoscience GERMANY
| | - Torben Baldau
- Universität Hamburg: Universitat Hamburg Department of Chemistry GERMANY
| | - Svenja Kerpa
- Universität Hamburg: Universitat Hamburg Department of Chemistry GERMANY
| | | | - Bing Qi
- Universität Hamburg: Universitat Hamburg Center for Hybrid Nanostructure GERMANY
| | - Yang Liu
- Universität Hamburg: Universitat Hamburg Center for Hybrid Nanostructure GERMANY
| | - Wolfgang J. Parak
- Universität Hamburg: Universitat Hamburg Center for Hybrid Nanostructure GERMANY
| | - Wolfgang Maison
- University of Hamburg Chemistry Bundesstr. 45 20146 Hamburg GERMANY
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13
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Váradi B, Lihi N, Bunda S, Nagy A, Simon G, Kéri M, Papp G, Tircsó G, Esteban-Gómez D, Platas-Iglesias C, Kálmán FK. Physico-Chemical Characterization of a Highly Rigid Gd(III) Complex Formed with a Phenanthroline Derivative Ligand. Inorg Chem 2022; 61:13497-13509. [PMID: 35972786 DOI: 10.1021/acs.inorgchem.2c02050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The discovery of the nephrogenic systemic fibrosis (NSF) and its link with the in vivo dissociation of certain Gd(III)-based contrast agents (CAs) applied in the magnetic resonance imaging (MRI) induced a still growing research to replace the compromised agents with safer alternatives. In recent years, several ligands were designed to exploit the luminescence properties of the lanthanides, containing structurally constrained aromatic moieties, which may form rigid Gd(III) complexes. One of these ligands is (1,10-phenanthroline-2,9-diyl)bis(methyliminodiacetic acid) (H4FENTA) designed and synthesized to sensitize Eu(III) and Tb(III) luminescence. Our results show that the conditional stability of the [Gd(FENTA)]- chelate calculated for physiological pH (pGd = 19.7) is similar to those determined for [Gd(DTPA)]2- (pGd = 19.4) and [Gd(DOTA)]- (pGd = 20.1), routinely used in the clinical practice. The [Gd(FENTA)]- complex is remarkably inert with respect to its dissociation (t1/2 = 872 days at pH = 7 and 25 °C); furthermore, its relaxivity values determined at different field strengths and temperatures (e.g., r1p = 4.3 mM-1s-1at 60 MHz and 37 °C) are ca. one unit higher than those of [Gd(DTPA)]2- (r1p = 3.4 mM-1 s-1) and [Gd(DOTA)]- (r1p = 3.1 mM-1 s-1) under the same conditions. Moreover, significant improvement on the relaxivity was observed in the presence of serum proteins (r1p = 6.9 mM-1 s-1 at 60 MHz and 37 °C). The luminescence lifetimes recorded in H2O and D2O solutions indicate the presence of a water molecule (q = 1) in the inner sphere of the complex directly coordinated to the metal ion, possessing a relatively high water exchange rate (kex298 = 29(2) × 106 s-1). The acceleration of the water exchange can be explained by the steric compression around the water binding site due to the rigid structure of the complex, which was supported by DFT calculations. On the basis of these results, ligands containing a phenanthroline platform have great potential in the design of safer Gd(III) agents for MRI.
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Affiliation(s)
- Balázs Váradi
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary.,Doctoral School of Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Norbert Lihi
- ELKH-DE Mechanisms of Complex Homogeneous and Heterogeneous Chemical Reactions Research Group, Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Szilvia Bunda
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Antónia Nagy
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Gréta Simon
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Mónika Kéri
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Gábor Papp
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Gyula Tircsó
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - David Esteban-Gómez
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, Univer-sidade da Coruña, A Coruña, Galicia 15071, Spain
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, Univer-sidade da Coruña, A Coruña, Galicia 15071, Spain
| | - Ferenc K Kálmán
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
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14
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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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15
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Kofod N, Nawrocki P, Sørensen TJ. Arel: Investigating [Eu(H 2O) 9] 3+ Photophysics and Creating a Method to Bypass Luminescence Quantum Yield Determinations. J Phys Chem Lett 2022; 13:3096-3104. [PMID: 35357175 DOI: 10.1021/acs.jpclett.2c00418] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Lanthanide luminescence has been treated separate from molecular photophysics, although the underlying phenomena are the same. As the optical transitions observed in the trivalent lanthanide ions are forbidden, they do belong to the group that molecular photophysics has yet to conquer, yet the experimental descriptors remain valid. Herein, the luminescence quantum yields (ϕlum), luminescence lifetimes (τobs), oscillator strengths (f), and the rates of nonradiative (knr) and radiative (kr ≡ A) deactivation of [Eu(H2O)9]3+ were determined. Further, it was shown that instead of a full photophysical characterization, it is possible to relate changes in transition probabilities to the relative parameter Arel, which does not require reference data. While Arel does not afford comparisons between experiments, it resolves emission intensity changes due to emitter properties from intensity changes due to environmental effects and differences in the number of photons absorbed. When working with fluorescence this may seem trivial; when working with lanthanide luminescence it is not.
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Affiliation(s)
- Nicolaj Kofod
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Patrick Nawrocki
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Thomas Just Sørensen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
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16
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Matsumoto M, Reid J, Byeman C, Evbuomwan O. Supramolecular Enhancement of Antenna‐sensitized Europium(III) Luminescence by Cucurbit[7]uril Complexation. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202101003] [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)
- Masaomi Matsumoto
- Department of Chemistry and Biochemistry Gonzaga University WA, 99258 Spokane United States
| | - Jon Reid
- Department of Chemistry and Biochemistry Gonzaga University WA, 99258 Spokane United States
| | - Connor Byeman
- Department of Chemistry and Biochemistry Gonzaga University WA, 99258 Spokane United States
| | - Osasere Evbuomwan
- Department of Chemistry University of San Francisco CA, 94117 San Francisco United States
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17
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Storm Thomsen M, Parsons S, Sørensen TJ. Invisible strings. The first single crystal of the cTSAP form of [Eu(DOTA)(H 2O)] − has an electronic structure similar to one of the reported cSAP forms. Dalton Trans 2022; 51:15725-15733. [DOI: 10.1039/d2dt02633c] [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
Counter ions can be used to tune the solid state structure of Eu·DOTA between the cSAP and cTSAP form, but the electronic properties does not match the observations seen in solution.
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Affiliation(s)
- Maria Storm Thomsen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Simon Parsons
- School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3FJ, Scotland, UK
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
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18
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Storm Thomsen M, Sørensen TJ. Delicate, a study of the structural changes in ten-coordinated La( iii), Ce( iii), Pr( iii), Nd( iii), Sm( iii) and Eu( iii) sulfates. Dalton Trans 2022; 51:8964-8974. [DOI: 10.1039/d2dt00832g] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A study of doped ten-coordinated structures of the lanthanide(iii) crystals series, K6[Ln2(SO4)6] (Ln(iii) = La, Ce, Pr) and K5Na[Ln2(SO4)6] (Ln(iii) = Nd, Sm, Eu) to determine luminescence from Eu(iii) in distorted host lattices.
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Affiliation(s)
- Maria Storm Thomsen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Thomas Just Sørensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
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19
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Synthesis, structure, phase controlled colour tuning of dinuclear Pr(III) and Tb(III) complexes with fluorinated β-diketone and heterocyclic Lewis base as UV light converters. Polyhedron 2022. [DOI: 10.1016/j.poly.2021.115592] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Ju H, Horita H, Iwase M, Kaneko N, Yagi KI, Ikeda M, Kuwahara S, Habata Y. Bis-Argentivorous Molecules Bridged by Phenyl and 4,4'-Biphenyl Groups: Structural and Dynamic Behavior of Silver Complexes. Inorg Chem 2021; 60:15159-15168. [PMID: 34587442 DOI: 10.1021/acs.inorgchem.1c01500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bis-argentivorous molecules (La and Lb), which have phenyl and 4,4'-biphenyl groups as linkers, have been prepared. The structures of Ag+ complexes with the new ligands (La and Lb) were investigated in solution and the solid state. The CSI-MS and 1H NMR titration of La and Lb with Ag+ show 1:1 and 1:2 complexes depending on the [Ag+]:[L] ratios. In the solid-state structures, single crystals of La and Lb with 2 equiv of Ag+ were prepared. X-ray crystallography of the silver(I) complexes with La and Lb showed that an intramolecular racemic structure (Δ(δδδδ)Λ(λλλλ) form) and a racemic mixture of Δ(δδδδ)Δ(δδδδ) and Λ(λλλλ)Λ(λλλλ) forms were formed, respectively. The dynamic 1H NMR studies suggest the following: (i) the activation entropies (ΔS⧧) of the side arm rotations in the Ag+ complex with La were all negative, indicating restricted rotation of the side arms due to their shortness, and (ii) the ΔS⧧ values of the Ag+ complexes with Lb were negative only when the side arms of both cyclens rotated simultaneously, and the ΔS⧧ values for the 1:1 and 1:2 complexes were positive when one cyclen side arm was rotated. These values of ΔS⧧ indicate that the biphenyl side arms between the two cyclens are not long enough to rotate the ring freely.
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Affiliation(s)
| | | | | | | | | | - Mari Ikeda
- Education Center, Faculty of Engineering, Chiba Institute of Technology, 2-1-1 Shibazono, Narashino, Chiba 275-0023, Japan
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Kofod N, Nielsen LG, Sørensen TJ. Temperature Dependence of Fundamental Photophysical Properties of [Eu(MeOH- d4) 9] 3+ Solvates and [Eu·DOTA(MeOH- d4)] - Complexes. J Phys Chem A 2021; 125:8347-8357. [PMID: 34546039 DOI: 10.1021/acs.jpca.1c04994] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The trivalent lanthanide ions show optical transitions between energy levels within the 4f shell. All these transitions are formally forbidden according to the quantum mechanical selection rules used in molecular photophysics. Nevertheless, highly luminescent complexes can be achieved, and terbium(III) and europium(III) ions are particularly efficient emitters. This report started when an apparent lack of data in the literature led us to revisit the fundamental photophysics of europium(III). The photophysical properties of two complexes-[Eu·DOTA(MeOH-d4)]- and [Eu(MeOH-d4)9]3+-were investigated in deuterated methanol at five different temperatures. Absorption spectra showed decreased absorbance as the temperature was increased. Luminescence spectra and time-resolved emission decay profiles showed a decrease in intensity and lifetime as the temperature was increased. Having corrected the emission spectra for the actual number of absorbed photons and differences in the non-radiative pathways, the relative emission probability was revealed. These were found to increase with increasing temperature. The transition probability for luminescence was shown to increase with temperature, while the transition probability for light absorption decreased. The changes in transition probabilities were correlated with a change in the symmetry of the absorber or emitter, with an average increase in symmetry lowering absorbance and access to more asymmetric structures increasing the emission rate constant. Determining luminescence quantum yields and the Einstein coefficient for spontaneous emission allowed us to conclude that lowering symmetry increases both. Furthermore, it was found that collisional self-quenching is an issue for lanthanide luminescence, when high concentrations are used. Finally, detailed analysis revealed results that show the so-called "Werts' method" for calculating radiative lifetimes and intrinsic quantum yields is based on assumptions that do not hold for the two systems investigated here. We conclude that we are lacking a good theoretical description of the intraconfigurational f-f transitions, and that there are still aspects of fundamental lanthanide photophysics to be explored.
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Affiliation(s)
- Nicolaj Kofod
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Lea Gundorff Nielsen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Thomas Just Sørensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
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22
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Vetsova VA, Fisher KR, Lumpe H, Schäfer A, Schneider EK, Weis P, Daumann LJ. Pyrroloquinoline Quinone Aza-Crown Ether Complexes as Biomimetics for Lanthanide and Calcium Dependent Alcohol Dehydrogenases*. Chemistry 2021; 27:10087-10098. [PMID: 33872420 PMCID: PMC8361747 DOI: 10.1002/chem.202100346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Indexed: 12/23/2022]
Abstract
Understanding the role of metal ions in biology can lead to the development of new catalysts for several industrially important transformations. Lanthanides are the most recent group of metal ions that have been shown to be important in biology, that is, in quinone‐dependent methanol dehydrogenases (MDH). Here we evaluate a literature‐known pyrroloquinoline quinone (PQQ) and 1‐aza‐15‐crown‐5 based ligand platform as scaffold for Ca2+, Ba2+, La3+ and Lu3+ biomimetics of MDH and we evaluate the importance of ligand design, charge, size, counterions and base for the alcohol oxidation reaction using NMR spectroscopy. In addition, we report a new straightforward synthetic route (3 steps instead of 11 and 33 % instead of 0.6 % yield) for biomimetic ligands based on PQQ. We show that when studying biomimetics for MDH, larger metal ions and those with lower charge in this case promote the dehydrogenation reaction more effectively and that this is likely an effect of the ligand design which must be considered when studying biomimetics. To gain more information on the structures and impact of counterions of the complexes, we performed collision induced dissociation (CID) experiments and observe that the nitrates are more tightly bound than the triflates. To resolve the structure of the complexes in the gas phase we combined DFT‐calculations and ion mobility measurements (IMS). Furthermore, we characterized the obtained complexes and reaction mixtures using Electron Paramagnetic Resonance (EPR) spectroscopy and show the presence of a small amount of quinone‐based radical.
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Affiliation(s)
- Violeta A Vetsova
- Department of Chemistry, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, 81377, Munich, Germany
| | - Katherine R Fisher
- Department of Chemistry, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, 81377, Munich, Germany
| | - Henning Lumpe
- Department of Chemistry, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, 81377, Munich, Germany
| | - Alexander Schäfer
- Karlsruhe Institute of Technology, Institute of Physical Chemistry, Fritz-Haber-Weg 2, 76128, Karlsruhe, Germany
| | - Erik K Schneider
- Karlsruhe Institute of Technology, Institute of Physical Chemistry, Fritz-Haber-Weg 2, 76128, Karlsruhe, Germany
| | - Patrick Weis
- Karlsruhe Institute of Technology, Institute of Physical Chemistry, Fritz-Haber-Weg 2, 76128, Karlsruhe, Germany
| | - Lena J Daumann
- Department of Chemistry, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, 81377, Munich, Germany
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23
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Kofod N, Nawrocki P, Platas-Iglesias C, Sørensen TJ. Electronic Structure of Ytterbium(III) Solvates-a Combined Spectroscopic and Theoretical Study. Inorg Chem 2021; 60:7453-7464. [PMID: 33949865 DOI: 10.1021/acs.inorgchem.1c00743] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The wide range of optical and magnetic properties of lanthanide(III) ions is associated with their intricate electronic structures which, in contrast to lighter elements, is characterized by strong relativistic effects and spin-orbit coupling. Nevertheless, computational methods are now capable of describing the ladder of electronic energy levels of the simpler trivalent lanthanide ions, as well as the lowest energy term of most of the series. The electronic energy levels result from electron configurations that are first split by spin-orbit coupling into groups of energy levels denoted by the corresponding Russell-Saunders terms. Each of these groups are then split by the ligand field into the actual electronic energy levels known as microstates or sometimes mJ levels. The ligand-field splitting directly informs on the coordination geometry and is a valuable tool for determining the structure and thus correlating the structure and properties of metal complexes in solution. The issue with lanthanide complexes is that the determination of complex structures from ligand-field splitting remains a very challenging task. In this paper, the optical spectra-absorption, luminescence excitation, and luminescence emission-of ytterbium(III) solvates were recorded in water, methanol, dimethyl sulfoxide (DMSO), and N,N-dimethylformamide (DMF). The electronic energy levels, that is, the microstates, were resolved experimentally. Subsequently, density functional theory calculations were used to model the structures of the solvates, and ab initio relativistic complete active space self-consistent field calculations (CASSCF) were employed to obtain the microstates of the possible structures of each solvate. By comparing the experimental and theoretical data, it was possible to determine both the coordination number and solution structure of each solvate. In water, methanol, and N,N-dimethylformamide, the solvates were found to be eight-coordinated and have a square antiprismatic coordination geometry. In DMSO, the speciation was found to be more complicated. The robust methodology developed for comparing experimental spectra and computational results allows the solution structures of homoleptic lanthanide complexes to be determined.
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Affiliation(s)
- Nicolaj Kofod
- Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Patrick Nawrocki
- Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
| | - Thomas Just Sørensen
- Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
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24
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Arnedo-Sanchez L, Smith KF, Deblonde GJP, Carter KP, Moreau LM, Rees JA, Tratnjek T, Booth CH, Abergel RJ. Combining the Best of Two Chelating Titans: A Hydroxypyridinone-Decorated Macrocyclic Ligand for Efficient and Concomitant Complexation and Sensitized Luminescence of f-Elements. Chempluschem 2021; 86:483-491. [PMID: 33733616 DOI: 10.1002/cplu.202100083] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/02/2021] [Indexed: 12/11/2022]
Abstract
An ideal chelator for f-elements features rapid kinetics of complexation, high thermodynamic stability, and slow kinetics of dissociation. Here we present the facile synthesis of a macrocyclic ligand bearing four 1-hydroxy-2-pyridinone units linked to a cyclen scaffold that rapidly forms thermodynamically stable complexes with lanthanides (Sm3+ , Eu3+ , Tb3+ , Dy3+ ) and a representative late actinide (Cm3+ ) in aqueous media and concurrently sensitizes them. Extended X-ray absorption fine structure (EXAFS) spectroscopy revealed an increase in the Ln/An-O bond lengths following the trend Cm>Eu>Tb and EXAFS data were compatible with time-resolved luminescence studies, which indicated one to two water molecules in the inner metal coordination sphere of Eu(III) and two water molecules for the Cm(III) complex. Spectrofluorimetric ligand competition titrations against DTPA confirmed the high thermodynamic stability of DOTHOPO complexes, with pM values between 19.9(1) and 21.9(2).
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Affiliation(s)
- Leticia Arnedo-Sanchez
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kurt F Smith
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Gauthier J-P Deblonde
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Glenn T. Seaborg Institute, Physical & Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Korey P Carter
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Liane M Moreau
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Julian A Rees
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Toni Tratnjek
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Corwin H Booth
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Rebecca J Abergel
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Department of Nuclear Engineering, University of California, Berkeley, CA 94709, USA
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25
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Kiraev SR, Mathieu E, Siemens F, Kovacs D, Demeyere E, Borbas KE. Lanthanide(III) Complexes of Cyclen Triacetates and Triamides Bearing Tertiary Amide-Linked Antennae. Molecules 2020; 25:molecules25225282. [PMID: 33198318 PMCID: PMC7698001 DOI: 10.3390/molecules25225282] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 01/08/2023] Open
Abstract
The coordination compounds of the trivalent lanthanide ions (Ln(III)) have unique photophysical properties. Ln(III) excitation is usually performed through a light-harvesting antenna. To enable Ln(III)-based emitters to reach their full potential, an understanding of how complex structure affects sensitization and quenching processes is necessary. Here, the role of the linker between the antenna and the metal binding fragment was studied. Four macrocyclic ligands carrying coumarin 2 or 4-methoxymethylcarbostyril sensitizing antennae linked to an octadentate macrocyclic ligand binding site were synthesized. Complexation with Ln(III) (Ln = La, Sm, Eu, Gd, Tb, Yb and Lu) yielded species with overall −1, 0, or +2 and +3-charge. Paramagnetic 1H NMR spectroscopy indicated subtle differences between the coumarin- and carbostyril-carrying Eu(III) and Yb(III) complexes. Cyclic voltammetry showed that the effect of the linker on the Eu(III)/Eu(II) apparent reduction potential was dependent on the electronic properties of the N-substituent. The Eu(III), Tb(III) and Sm(III) complexes were all luminescent. Coumarin-sensitized complexes were poorly emissive; photoinduced electron transfer was not a major quenching pathway in these species. These results show that seemingly similar emitters can undergo very different photophysical processes, and highlight the crucial role the linker can play.
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26
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Andres J, Chauvin AS. Colorimetry of Luminescent Lanthanide Complexes. Molecules 2020; 25:molecules25174022. [PMID: 32899208 PMCID: PMC7570272 DOI: 10.3390/molecules25174022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 08/31/2020] [Indexed: 12/17/2022] Open
Abstract
Europium, terbium, dysprosium, and samarium are the main trivalent lanthanide ions emitting in the visible spectrum. In this work, the potential of these ions for colorimetric applications and colour reproduction was studied. The conversion of spectral data to colour coordinates was undertaken for three sets of Ln complexes composed of different ligands. We showed that Eu is the most sensitive of the visible Ln ions, regarding ligand-induced colour shifts, due to its hypersensitive transition. Further investigation on the spectral bandwidth of the emission detector, on the wavelengths’ accuracy, on the instrumental correction function, and on the use of incorrect intensity units confirm that the instrumental correction function is the most important spectrophotometric parameter to take into account in order to produce accurate colour values. Finally, we established and discussed the entire colour range (gamut) that can be generated by combining a red-emitting Eu complex with a green-emitting Tb complex and a blue fluorescent compound. The importance of choosing a proper white point is demonstrated. The potential of using different sets of complexes with different spectral fingerprints in order to obtain metameric colours suitable for anti-counterfeiting is also highlighted. This work answers many questions that could arise during a colorimetric analysis of luminescent probes.
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Affiliation(s)
- Julien Andres
- Section of Chemistry and Chemical Engineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Correspondence: (J.A.); (A.-S.C.); Tel.: +41-21-693-7455 (J.A.); +41-21-693-9824 (A.-S.C.)
| | - Anne-Sophie Chauvin
- Section of Chemistry and Chemical Engineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Institut des Sciences et Ingénierie Chimique, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Correspondence: (J.A.); (A.-S.C.); Tel.: +41-21-693-7455 (J.A.); +41-21-693-9824 (A.-S.C.)
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27
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Dasari S, Maparu AK, Abbas Z, Kumar P, Birla H, Sivakumar S, Patra AK. Bimetallic Europium and Terbium Complexes Containing Substituted Terpyridines and the NSAID Drug Tolfenamic Acid: Structural Differences, Luminescence Properties, and Theranostic Applications. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000443] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Srikanth Dasari
- Department of Chemistry; Indian Institute of Technology Kanpur; 208016 Kanpur Uttar Pradesh India
| | - Auhin Kumar Maparu
- Department of Chemical Engineering; Center for Environmental Science and Engineering; Indian Institute of Technology Kanpur; 208016 Kanpur Uttar Pradesh India
| | - Zafar Abbas
- Department of Chemistry; Indian Institute of Technology Kanpur; 208016 Kanpur Uttar Pradesh India
| | - Priyaranjan Kumar
- Department of Chemistry; Indian Institute of Technology Kanpur; 208016 Kanpur Uttar Pradesh India
| | - Hariom Birla
- Department of Chemistry; Indian Institute of Technology Kanpur; 208016 Kanpur Uttar Pradesh India
| | - Sri Sivakumar
- Department of Chemical Engineering; Center for Environmental Science and Engineering; Indian Institute of Technology Kanpur; 208016 Kanpur Uttar Pradesh India
| | - Ashis K. Patra
- Department of Chemistry; Indian Institute of Technology Kanpur; 208016 Kanpur Uttar Pradesh India
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28
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Kovacs D, Mathieu E, Kiraev SR, Wells JAL, Demeyere E, Sipos A, Borbas KE. Coordination Environment-Controlled Photoinduced Electron Transfer Quenching in Luminescent Europium Complexes. J Am Chem Soc 2020; 142:13190-13200. [DOI: 10.1021/jacs.0c05518] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Daniel Kovacs
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Emilie Mathieu
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Salauat R. Kiraev
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Jordann A. L. Wells
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Ellen Demeyere
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Agnès Sipos
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - K. Eszter Borbas
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
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29
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Podyachev SN, Sudakova SN, Nagimov RN, Masliy AN, Syakaev VV, Lapaev DV, Buzyurova DN, Babaev VM, Gimazetdinova GS, Kuznetsov AM, Mustafina AR. A simple synthetic approach to enhance the thermal luminescence sensitivity of Tb 3+ complexes with thiacalix[4]arene derivatives through upper-rim bromination. Dalton Trans 2020; 49:8298-8313. [PMID: 32514517 DOI: 10.1039/d0dt00709a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The present work for the first time reports an application of the thiacalix[4]arene scaffold for the preparation of Tb3+ complexes possessing high thermal luminescence sensitivity in the physiological temperature range of 20-50 °C. Non-substituted thiacalix[4]arenes form luminescent complexes with Tb3+ ions, but they do not reveal any meaningful thermal sensitivity. To solve this problem, an upper-rim bromination of thiacalix[4]arenes, as well as distal bromination along with the embedding of two 1,3-diketone substituents are proposed as new simple synthetic approaches to enhance the thermal luminescence sensitivity of the Tb3+ complexes. A combination of mass spectrometry, NMR, UV-Vis and luminescence spectroscopy with quantum chemical calculations reveals a dimeric structure of the complexes formed by thiacalix[4]arenes with Tb3+ ions in DMF solutions. The steady-state luminescence of the Tb3+ complexes has demonstrated more than one order higher thermal sensitivity for the complexes of bromo-substituted ligands in comparison with the non-substituted thiacalix[4]arenes. The reasons for such behavior are discussed. The results highlight new opportunities for the thiacalix[4]arene platform for controlling ligand-to-metal energy transfer in terbium complexes and tuning their thermo-responsive luminescence properties.
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Affiliation(s)
- Sergey N Podyachev
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center of RAS, Arbuzov str., 8, 420088, Kazan, Russian Federation.
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30
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Wydra K, Kobyłka MJ, Lis T, Ślepokura K, Lisowski J. Versatile Binding Modes of Chiral Macrocyclic Amine towards Rare Earth Ions. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000247] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Karol Wydra
- Department of Chemistry University of Wrocław 14 F. Joliot‐Curie 50‐383 Wrocław Poland
| | - Michał J. Kobyłka
- Department of Chemistry University of Wrocław 14 F. Joliot‐Curie 50‐383 Wrocław Poland
| | - Tadeusz Lis
- Department of Chemistry University of Wrocław 14 F. Joliot‐Curie 50‐383 Wrocław Poland
| | - Katarzyna Ślepokura
- Department of Chemistry University of Wrocław 14 F. Joliot‐Curie 50‐383 Wrocław Poland
| | - Jerzy Lisowski
- Department of Chemistry University of Wrocław 14 F. Joliot‐Curie 50‐383 Wrocław Poland
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Bridou L, Nielsen LG, Sørensen TJ. Using europium(III) complex of 1,4,7,10-tetraazacyclododecane-1,4,7-triacedic acid Eu.DO3A as a luminescent sensor for bicarbonate. J RARE EARTH 2020. [DOI: 10.1016/j.jre.2019.11.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Del Giorgio E, Sørensen TJ. HOCl Responsive Lanthanide Complexes Using Hydroquinone Caging Units. Molecules 2020; 25:E1959. [PMID: 32340115 PMCID: PMC7221670 DOI: 10.3390/molecules25081959] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 01/14/2023] Open
Abstract
Redox biology is still looking for tools to monitor redox potential in cellular biology and, despite a large and sustained effort, reliable molecular probes have yet to emerge. In contrast, molecular probes for reactive oxygen and nitrogen have been widely explored. In this manuscript, three kinetically inert lanthanide complexes that selectively react with hypochlorous acid are prepared and characterized. The design is based on 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A) and 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (DO2A) ligands appended with one or two redox active hydroquinone derived arms, thereby forming octadentate ligands ideally suited to complex trivalent lanthanide ions. The three complexes are found to react selectively with hypochlorous acid to form highly symmetric lanthanide(III) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacedic acid (DOTA) complexes. The conversion of the probe to [Ln.DOTA]- is followed by luminescence, absorption, and NMR spectroscopy in a model system comprised of a Triton-X modified HEPES buffer. It was concluded that the design principle works, and that simple caging units like hydroquinones can work well in conjugation with lanthanide(III) complexes.
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Affiliation(s)
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken5, 2100 København Ø, Denmark;
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Tircsó G, Tircsóné Benyó E, Garda Z, Singh J, Trokowski R, Brücher E, Sherry AD, Tóth É, Kovács Z. Comparison of the equilibrium, kinetic and water exchange properties of some metal ion-DOTA and DOTA-bis(amide) complexes. J Inorg Biochem 2020; 206:111042. [PMID: 32146160 DOI: 10.1016/j.jinorgbio.2020.111042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/18/2022]
Abstract
The 1,7-diacetate-4,10-diacetamide substituted 1,4,7,10-tetraazacyclododecane structural unit is common to several responsive Magnetic Resonance Imaging (MRI) contrast agents (CAs). While some of these complexes (agents capable of sensing fluctuations in Zn2+, Ca2+ etc. ions) have already been tested in vivo, the detailed physico-chemical characterization of such ligands have not been fully studied. To fill this gap, we synthesized a representative member of this ligand family possessing two acetate and two n-butylacetamide pendant side-arms (DO2A2MnBu = 1,4,7,10-tetraazacyclodoecane-1,7-di(acetic acid)-4,10-di(N-butylacetamide)), and studied its complexation properties with some essential metal and a few lanthanide(III) (Ln(III)) ions. Our studies revealed that the ligand basicity, the stability of metal ion complexes, the trend of stability constants along the Ln(III) series, the formation rates of the Ln(III) complexes and the exchange rate of the bound water molecule in the Gd(III) complex fell between those of Ln(DOTA)- and Ln(DOTA-tetra(amide))3+ complexes (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, DOTAM = 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane). The only exception is the stability of Cu(DO2A2MnBu) which was found to be only slightly lower than that of Cu(DOTA)2- (log KCuL = 19.85 vs. 21.98). This is likely reflects exclusive coordination of the negatively charged acetate donor atoms to the Cu2+ ion forming an octahedral complex with the amides remaining uncoordinated. The only anomaly observed during the study was the rates of acid assisted dissociation of the Ln(III) complexes, which occur at a rate similar to those observed for the Ln(DOTA)- complexes. These data indicate that even though the Ln(DO2A2MnBu)+ complexes have lower thermodynamic stabilities, their kinetic inertness should be sufficient for in vivo use.
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Affiliation(s)
- Gyula Tircsó
- University of Debrecen, Department of Physical Chemistry, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Enikő Tircsóné Benyó
- University of Debrecen, Department of Physical Chemistry, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Zoltán Garda
- University of Debrecen, Department of Physical Chemistry, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Jaspal Singh
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, United States of America
| | - Robert Trokowski
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, United States of America; Department of Chemistry, University of Texas at Dallas, P.O. Box 830660, Richardson, TX 75083, United States of America
| | - Ernő Brücher
- University of Debrecen, Department of Physical Chemistry, Egyetem tér 1, Debrecen H-4032, Hungary
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, United States of America; Department of Chemistry, University of Texas at Dallas, P.O. Box 830660, Richardson, TX 75083, United States of America
| | - Éva Tóth
- Centre de Biophysique Moléculaire, CNRS, rue Charles Sadron, 45071 Orléans, Cedex 2, France
| | - Zoltán Kovács
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, United States of America.
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Nawrocki PR, Kofod N, Juelsholt M, Jensen KMØ, Sørensen TJ. The effect of weighted averages when determining the speciation and structure–property relationships of europium(iii) dipicolinate complexes. Phys Chem Chem Phys 2020; 22:12794-12805. [DOI: 10.1039/d0cp00989j] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Europium(iii) dipicolinate complexes have been a model system in lanthanide solution chemistry for decades, here it is investigated in unprecedented detail.
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Affiliation(s)
- Patrick R. Nawrocki
- Nano-Science Center & Department of Chemistry
- University of Copenhagen
- 2100 København Ø
- Denmark
| | - Nicolaj Kofod
- Nano-Science Center & Department of Chemistry
- University of Copenhagen
- 2100 København Ø
- Denmark
| | - Mikkel Juelsholt
- Nano-Science Center & Department of Chemistry
- University of Copenhagen
- 2100 København Ø
- Denmark
| | - Kirsten M. Ø. Jensen
- 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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