1
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Cineus R, Abozeid SM, Sokolow GE, Spernyak JA, Morrow JR. Fe(III) T1 MRI Probes Containing Phenolate or Hydroxypyridine-Appended Triamine Chelates and a Coordination Site for Bound Water. Inorg Chem 2023; 62:16513-16522. [PMID: 37748050 DOI: 10.1021/acs.inorgchem.3c02344] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Fe(III) complexes containing a triamine framework and phenolate or hydroxypyridine donors are characterized and studied as T1 MRI probes. In contrast to most Fe(III) MRI probes of linear chelates reported to date, the ligands reported here are pentadentate to give six-coordinate complexes with a coordination site for inner-sphere water. The crystal structure of the complex containing unsubstituted phenolate donors, Fe(L1)Cl, shows a six-coordinate iron center and contains a chloride ligand that is displaced in water. Two additional derivatives are sufficiently water-soluble for study as MRI probes, including a complex with a hydroxypyridine group, Fe(L2), and a hydroxybenzoic acid group, Fe(L3). The pH potentiometric titrations give protonation constants of 7.2 and 7.5 for Fe(L2) and Fe(L3), respectively, which are assigned to deprotonation of the bound water. Changes in the electronic absorbance spectra of the complexes as a function of pH are consistent with the deprotonation of phenol pendants at acidic pH values. However, the inner-sphere water ligand of Fe(L2) and Fe(L3) does not exchange rapidly on the NMR timescale at pH 6.0 or 7.4, as shown by variable-temperature 17O NMR spectroscopy. The pH-dependent proton relaxivity profiles show a maximum in relaxivity at a near-neutral pH, suggesting that exchange of the protons of the bound water is an important contribution. Competitive binding studies with ethylenediaminetetraacetic acid (EDTA) show effective stability constants for Fe(L2) and Fe(L3) at pH 7.4 with log K values of 21.1 and 20.5, respectively. These two complexes are kinetically inert in carbonate phosphate buffer at 37 °C for several hours but transfer iron to transferrin. Fe(L2) and Fe(L3) show enhanced contrast in T1-weighted imaging analyses in BALB/c mice. These studies show that Fe(L2) clears through mixed renal and hepatobiliary routes, while Fe(L3) has a similar pharmacokinetic clearance profile to a macrocyclic Gd(III) contrast agent.
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Affiliation(s)
- Roy Cineus
- Department of Chemistry, University at Buffalo, The State University of New York Amherst, New York 14260, United States
| | - Samira M Abozeid
- Department of Chemistry, Faculty of Science, Mansoura University, El-Gomhoria Street, 35516 Mansoura, Egypt
| | - Gregory E Sokolow
- Department of Chemistry, University at Buffalo, The State University of New York Amherst, New York 14260, United States
| | - Joseph A Spernyak
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York 14263, United States
| | - Janet R Morrow
- Department of Chemistry, University at Buffalo, The State University of New York Amherst, New York 14260, United States
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2
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Martinon TLM, Pierre VC. Luminescent lanthanide probes for cations and anions: Promises, compromises, and caveats. Curr Opin Chem Biol 2023; 76:102374. [PMID: 37517109 PMCID: PMC10529829 DOI: 10.1016/j.cbpa.2023.102374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 06/28/2023] [Accepted: 07/01/2023] [Indexed: 08/01/2023]
Abstract
The long luminescence lifetimes and sharp emission bands of luminescent lanthanide complexes have long been recognized as invaluable strengths for sensing and imaging in complex aqueous biological or environmental media. Herein we discuss the recent developments of these probes for sensing metal ions and, increasingly, anions. Underappreciated in the field, buffers and metal hydrolysis influence the response of many responsive lanthanide probes. The inherent complexities arising from these interactions are further discussed.
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Affiliation(s)
- Thibaut L M Martinon
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis MN 55455, USA
| | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis MN 55455, USA.
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3
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Martinon TLM, Ramakrishnam Raju MV, Pierre VC. Kinetically Inert Macrocyclic Europium(III) Receptors for Phosphate. Inorg Chem 2023; 62:10064-10076. [PMID: 37339454 PMCID: PMC10389169 DOI: 10.1021/acs.inorgchem.2c03833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
The significant role that phosphate plays in environmental water pollution and biomedical conditions such as hyperphosphatemia highlights the need to develop robust receptors that can sequester the anion effectively and selectively from complex aqueous media. Toward that goal, four macrocyclic tris-bidentate 1,2-hydroxypyridonate (HOPO) europium(III) complexes containing either a cyclen, cyclam, TACN, or TACD ligand cap were synthesized and evaluated as phosphate receptors. The solubility of EuIII-TACD-HOPO in water was insufficient for luminescent studies. Whereas EuIII-cyclen-HOPO is eight coordinate with two inner-sphere water molecules, both EuIII-cyclam-HOPO and EuIII-TACN-HOPO are nine coordinate with three inner-sphere water molecules, suggesting that the two coordination states are very close in energy. As observed previously with linear analogues of tripodal HOPO complexes, there is no relationship between the number of inner-sphere water molecules and the affinity of the complex for phosphate. Whereas all three complexes do bind phosphate, EuIII-cyclen-HOPO has the highest affinity for phosphate with the anion displacing both of its inner-sphere water molecules. On the other hand, only one or two of the three inner-sphere water molecules of EuIII-TACN-HOPO and EuIII-cyclam-HOPO are displaced by phosphate, respectively. All three complexes are highly selective for phosphate over other anions, including arsenate. All three complexes are highly stable. EuIII-cyclen-HOPO and, to a lesser extent, EuIII-TACN-HOPO are more kinetically inert than the linear EuIII-Ser-HOPO. EuIII-cyclam-HOPO, on the other hand, is not. This study highlights the significant effect that minor changes in the ligand cap can have on both the ligand exchange rate and affinity for phosphate of tripodal 1,2-dihydroxypyridinonate complexes.
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Affiliation(s)
- Thibaut L M Martinon
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | | | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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4
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Johnson K, Driscoll DM, Damron JT, Ivanov AS, Jansone-Popova S. Size Selective Ligand Tug of War Strategy to Separate Rare Earth Elements. JACS AU 2023; 3:584-591. [PMID: 36873676 PMCID: PMC9976341 DOI: 10.1021/jacsau.2c00671] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/09/2023] [Accepted: 01/13/2023] [Indexed: 05/08/2023]
Abstract
Separating rare earth elements is a daunting task due to their similar properties. We report a "tug of war" strategy that employs a lipophilic and hydrophilic ligand with contrasting selectivity, resulting in a magnified separation of target rare earth elements. Specifically, a novel water-soluble bis-lactam-1,10-phenanthroline with an affinity for light lanthanides is coupled with oil-soluble diglycolamide that selectively binds heavy lanthanides. This two-ligand strategy yields a quantitative separation of the lightest (e.g., La-Nd) and heaviest (e.g., Ho-Lu) lanthanides, enabling efficient separation of neighboring lanthanides in-between (e.g., Sm-Dy).
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Affiliation(s)
- Katherine
R. Johnson
- Nuclear
Energy and Fuel Cycle Division, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Darren M. Driscoll
- Chemical
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Joshua T. Damron
- Chemical
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Alexander S. Ivanov
- Chemical
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Santa Jansone-Popova
- Chemical
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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5
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Huang SY, Pierre VC. Achieving Selectivity for Phosphate over Pyrophosphate in Ethanol with Iron(III)-Based Fluorescent Probes. JACS AU 2022; 2:1604-1609. [PMID: 35911450 PMCID: PMC9326827 DOI: 10.1021/jacsau.2c00200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two iron(III)-based molecular receptors employing 1,2-hydroxypyridinone ligands were developed for phosphate recognition and fluorescence sensing via indicator displacement assay (IDA). The tetra- and pentadentate ligands enable anion recognition by the iron(III) center via its remaining one or two open coordination sites. Weak protective coordination of fluorescein at those sites prevents the formation of μ-oxo dimers in aerated solutions. Its rapid and selective displacement by inorganic phosphate results in a 20-fold increase in the fluorescence of the indicator. Both receptors exhibit high affinity for inorganic phosphate and high selectivity over common competing anions, including halides, acetate, carbonate, and, remarkably, pyrophosphate as well as arsenate. Coordination of phosphate to the iron(III) center was confirmed by ATR-IR and 31P NMR spectroscopy.
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6
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Martinon TLM, Pierre VC. Luminescent Lanthanide Probes for Inorganic and Organic Phosphates. Chem Asian J 2022; 17:e202200495. [PMID: 35750633 PMCID: PMC9388549 DOI: 10.1002/asia.202200495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/19/2022] [Indexed: 11/09/2022]
Abstract
Inorganic and organic phosphates-including orthophosphate, nucleotides, and DNA-are some of the most fundamental anions in cellular biology, regulating numerous processes of both medical and environmental significance. The characteristic long lifetimes of emitting lanthanides, including the brighter europium(III) and terbium(III), make them ideally suited for the development of molecular probes for the detection of phosphates directly in complex aqueous media. Moreover, given their high oxophilicity and the exquisite sensitivity of their quantum yields to their hydration number, those luminescent lanthanides are perfect for the detection of phosphates. Herein we discuss the principles that have guided the recent developments of molecular probes selective for inorganic or organic phosphates and how these lanthanide complexes facilitate the study of numerous biological processes.
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Affiliation(s)
- Thibaut L M Martinon
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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7
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Santos MA, Irto A, Buglyó P, Chaves S. Hydroxypyridinone-Based Metal Chelators towards Ecotoxicity: Remediation and Biological Mechanisms. Molecules 2022; 27:1966. [PMID: 35335329 PMCID: PMC8950932 DOI: 10.3390/molecules27061966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/13/2022] [Accepted: 03/14/2022] [Indexed: 01/29/2023] Open
Abstract
Hydroxypyridinones (HPs) are recognized as excellent chemical tools for engineering a diversity of metal chelating agents, with high affinity for hard metal ions, exhibiting a broad range of activities and applications, namely in medical, biological and environmental contexts. They are easily made and functionalizable towards the tuning of their pharmacokinetic properties or the improving of their metal complex thermodynamic stabilities. In this review, an analysis of the recently published works on hydroxypyridinone-based ligands, that have been mostly addressed for environmental applications, namely for remediation of hard metal ion ecotoxicity in living beings and other biological matrices is carried out. In particular, herein the most recent developments in the design of new chelating systems, from bidentate mono-HP to polydentate multi-HP derivatives, with a structural diversity of soluble or solid-supported backbones are outlined. Along with the ligand design, an analysis of the relationship between their structures and activities is presented and discussed, namely associated with the metal affinity and the thermodynamic stability of the corresponding metal complexes.
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Affiliation(s)
- M. Amélia Santos
- Centro de Química Estrutural and Departamento de Engenharia Química, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
| | - Anna Irto
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale F. Stagno d’Alcontres, 31, I-98166 Messina, Italy;
| | - Péter Buglyó
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary;
| | - Sílvia Chaves
- Centro de Química Estrutural and Departamento de Engenharia Química, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
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8
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Wilharm RK, Ramakrishnam Raju MV, Hoefler JC, Platas-Iglesias C, Pierre VC. Exploiting the Fluxionality of Lanthanide Complexes in the Design of Paramagnetic Fluorine Probes. Inorg Chem 2022; 61:4130-4142. [PMID: 35196450 PMCID: PMC8966431 DOI: 10.1021/acs.inorgchem.1c03908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Fluorine-19 MRI is increasingly being considered as a tool for biomolecular imaging, but the very poor sensitivity of this technique has limited most applications. Previous studies have long established that increasing the sensitivity of 19F molecular probes requires increasing the number of fluorine nuclei per probe as well as decreasing their longitudinal relaxation time. The latter is easily achieved by positioning the fluorine atoms in close proximity to a paramagnetic metal ion such as a lanthanide(III). Increasing the number of fluorine atoms per molecule, however, is only useful inasmuch as all of the fluorine nuclei are chemically equivalent. Previous attempts to achieve this equivalency have focused on designing highly symmetric and rigid fluorinated macrocyclic ligands. A much simpler approach consists of exploiting highly fluxional lanthanide complexes with open coordination sites that have a high affinity for phosphated and phosphonated species. Computational studies indicate that LnIII-TREN-MAM is highly fluxional, rapidly interconverting between at least six distinct isomers. In neutral water at room temperature, LnIII-TREN-MAM binds two or three equivalents of fluorinated phosphonates. The close proximity of the 19F nuclei to the LnIII center in the ternary complex decreases the relaxation times of the fluorine nuclei up to 40-fold. Advantageously, the fluorophosphonate-bound lanthanide complex is also highly fluxional such that all 19F nuclei are chemically equivalent and display a single 19F signal with a small LIS. Dynamic averaging of fluxional fluorinated supramolecular assemblies thus produces effective 19F MR systems.
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Affiliation(s)
- Randall K Wilharm
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | | | - John C Hoefler
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Quıímica, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia Spain
| | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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9
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Pierre VC, Wilharm RK. Design Principles and Applications of Selective Lanthanide-Based Receptors for Inorganic Phosphate. Front Chem 2022; 10:821020. [PMID: 35198539 PMCID: PMC8859545 DOI: 10.3389/fchem.2022.821020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/11/2022] [Indexed: 01/07/2023] Open
Abstract
Phosphate is an anion of both environmental and medical significance. The increase in phosphate levels in surface waters due primarily to run-offs from fertilized agricultural fields causes widespread eutrophication and increasingly large dead-zones. Hyperphosphatemia, a condition in which blood phosphate levels are elevated, is a primary cause of increased mortality and morbidity in chronic or advanced kidney disease. Resolving both of these issues require, in part, new technology that could selectively sequester phosphate in water at neutral pH. The high hydration energy of phosphate, which prevents organic receptors from functioning in water with sufficient affinity, can be overcome via coordination to a hard metal ion. The hardness, oxophilicity and lability of lanthanide ions make them excellent candidates for the design of high affinity phosphate receptors. In this perspective, we discuss how the principles of lanthanide coordination chemistry can be exploited to design sensitive and selective receptors for phosphate. Unlike many supramolecular systems, these hosts do not recognize their anionic guests via directed electrostatic and hydrogen bonding interactions. Instead, the selectivity of our fluxional receptors is governed entirely by acid-base chemistry and electrostatic forces. Parameters that affect the affinity and selectivity of the receptors include the basicities of the coordinating ligand and of the targeted anion, the acidity of the lanthanide ion, and the geometry of the ligand. Uniquely, their affinity for phosphate can be readily tuned by orders of magnitude either by peripheral interactions or by the lanthanide ion itself without affecting their exquisite selectivity over competing anions such as bicarbonate and chloride.
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10
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Botár R, Molnár E, Garda Z, Madarasi E, Trencsényi G, Kiss J, Kálmán FK, Tircsó G. Synthesis and characterization of a stable and inert MnII-based ZnII responsive MRI probe for molecular imaging of glucose stimulated zinc secretion (GSZS). Inorg Chem Front 2022. [DOI: 10.1039/d1qi00501d] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A ZnII responsive MnII-based MRI contrast agent, [Mn(PC2A-DPA)], has been synthesized, investigated and applied in imaging studies. It shows high stability and excellent inertness and can be used to visualize glucose triggered ZnII release by MRI.
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Affiliation(s)
- Richárd Botár
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
- Doctoral School of Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
| | - Enikő Molnár
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
| | - Zoltán Garda
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
| | - Enikő Madarasi
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
- Doctoral School of Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
| | - György Trencsényi
- Department of Medical Imaging, Division of Nuclear Medicine, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
| | - János Kiss
- Department of Medical Imaging, Division of Nuclear Medicine, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
| | - Ferenc K. Kálmán
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
| | - Gyula Tircsó
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
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11
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Bodman SE, Breen C, Kirkland S, Wheeler S, Robertson E, Plasser F, Butler SJ. Sterically demanding macrocyclic Eu(iii) complexes for selective recognition of phosphate and real-time monitoring of enzymatically generated adenosine monophosphate. Chem Sci 2022; 13:3386-3394. [PMID: 35432862 PMCID: PMC8943852 DOI: 10.1039/d1sc05377a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/10/2022] [Indexed: 12/15/2022] Open
Abstract
The design of molecular receptors that bind and sense anions in biologically relevant aqueous solutions is a key challenge in supramolecular chemistry. The recognition of inorganic phosphate is particularly challenging because of its high hydration energy and pH dependent speciation. Adenosine monophosphate (AMP) represents a valuable but elusive target for supramolecular detection because of its structural similarity to the more negatively charged anions, ATP and ADP. We report two new macrocyclic Eu(iii) receptors capable of selectively sensing inorganic phosphate and AMP in water. The receptors contain a sterically demanding 8-(benzyloxy)quinoline pendant arm that coordinates to the metal centre, creating a binding pocket suitable for phosphate and AMP, whilst excluding potentially interfering chelating anions, in particular ATP, bicarbonate and lactate. The sensing selectivity of our Eu(iii) receptors follows the order AMP > ADP > ATP, which represents a reversal of the order of selectivity observed for most reported nucleoside phosphate receptors. We have exploited the unique host–guest induced changes in emission intensity and lifetime for the detection of inorganic phosphate in human serum samples, and for monitoring the enzymatic production of AMP in real-time. We present two new europium-based anion receptors that selectively bind to inorganic phosphate and AMP in aqueous media. Their sensing selectivity follows the order AMP > ADP > ATP, representing a reversal of the selectivity order observed for most nucleoside phosphate receptors.![]()
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Affiliation(s)
- Samantha E. Bodman
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
| | - Colum Breen
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
| | - Sam Kirkland
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
| | - Simon Wheeler
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
| | - Erin Robertson
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
| | - Felix Plasser
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
| | - Stephen J. Butler
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
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12
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Wilharm RK, Huang SY, Gugger IJ, Pierre VC. A Walk Across the Lanthanide Series: Trend in Affinity for Phosphate and Stability of Lanthanide Receptors from La(III) to Lu(III). Inorg Chem 2021; 60:15808-15817. [PMID: 34618431 DOI: 10.1021/acs.inorgchem.1c02462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The trend in affinity of two 1,2-hydroxypyridinonate lanthanide(III) receptors-LnIII-2,2-Li-HOPO and LnIII-3,3-Gly-HOPO (LnIII = LaIII, PrIII, NdIII, SmIII, EuIII, GdIII, TbIII, DyIII, HoIII, ErIII, TmIII, YbIII, and LuIII)-for phosphate across the series was investigated by luminescence spectroscopy via competition against the central europium(III) analog. Regardless of the ligand, the rare earth receptors display a steep and continuous increase in affinity for their phosphate guest across the series, with the later lanthanides displaying the highest affinity for the oxyanion. This trend mirrors that of the stability of the lanthanide receptors, which also increases significantly and continuously from LaIII to LuIII. For these two ligands, the ionic radius of a rare earth, a parameter directly linked to its Lewis acidity, correlates strongly with its affinity for anions, regardless of whether that anion is the one coordinating it (in this case the 1,2-hydroxypyridinonate ligand) or the guest targeted by the lanthanide receptor (in this case phosphate). These observations are indicative of a lack of steric hindrance for coordination of phosphate. Advantageously, increased efficacy of the lanthanide receptor comes with increased stability. The remarkably high stability of LuIII-2,2-Li-HOPO, combined with its high affinity for phosphate, makes it a particularly promising candidate for translational application to medical or environmental sequestration of phosphate since the higher stability will further reduce the risk of the rare earth leaching during anion separation. The unusually large difference in stability between lanthanide complexes (the LuIII complex of 2,2-Li-HOPO is at least 7 orders of magnitude more stable than the LaIII one) bodes well for potential applications in rare earth separation.
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Affiliation(s)
- Randall K Wilharm
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Sheng-Yin Huang
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Isabel J Gugger
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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13
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Harris S, Peterson KL, Bailie KM, Tower CD, Rundle BK, Ricks TR, Pierre VC. Design and Evaluation of the Environmental Outreach Activity for Middle School Students. ACS OMEGA 2020; 5:25175-25187. [PMID: 33043196 PMCID: PMC7542590 DOI: 10.1021/acsomega.0c03194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
The design and development of an outreach activity targeted at 6th grade middle school students, which aims to determine the level of phosphate in samples of water from nearby lakes and streams, are detailed. Several parameters were noted as key to the successful implementation of this activity in a school setting and to it being well-received by both students and teachers. These include the hands-on nature of the experiment, the use of professional scientific equipment and protocols, and the relevance to everyday life and nearby societal issues. Incorporation of the activity into the middle school science curriculum and educational standards are discussed. Qualitative data indicate that the outreach activity was positively received by students and teachers alike. Statistical differences were found between schools and gender even before performing the activity, suggesting that not all student audiences have the same predisposition for science. Overall, the outreach activity appeared to increase stronger endorsements of positive attitudes toward science. Cumulatively, these results suggest that the outreach activity was well-received and engaging and indicate that it increases positive attitudes toward science, though more in-depth and longitudinal analyses are necessary for future studies.
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Affiliation(s)
- Sarah
M. Harris
- Department
of Chemistry, State University of New York
Oswego, Oswego, New York 13126, United States
- Department
of Chemistry & Biochemistry, Benedictine
College, Atchison, Kansas 66002, United States
| | - Katie L. Peterson
- Department
of Chemistry, Bemidji State University, Bemidji, Minnesota, 56601, United States
| | - Kate M. Bailie
- Department
of Chemistry, State University of New York
Oswego, Oswego, New York 13126, United States
| | - Chris D. Tower
- Bemidji
Middle School, Bemidji, Minnesota 56601, United States
| | - Brian K. Rundle
- Department
of Neurology, David Geffen School of Medicine
at University of California Los Angeles, Los Angeles, California 90095, United States
| | - Travis R. Ricks
- Department
of Psychology, Bemidji State University, Bemidji, Minnesota, 56601, United States
| | - Valérie C. Pierre
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota, 55455, United States
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14
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Joaqui-Joaqui MA, Pandey MK, Bansal A, Raju MVR, Armstrong-Pavlik F, Dundar A, Wong HL, DeGrado TR, Pierre VC. Catechol-Based Functionalizable Ligands for Gallium-68 Positron Emission Tomography Imaging. Inorg Chem 2020; 59:12025-12038. [DOI: 10.1021/acs.inorgchem.0c00975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- M. Andrey Joaqui-Joaqui
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mukesh K. Pandey
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Aditya Bansal
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | | | - Fiona Armstrong-Pavlik
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ayca Dundar
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Henry L. Wong
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery & Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Timothy R. DeGrado
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Valérie C. Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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15
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Huang SY, Qian M, Pierre VC. The Ligand Cap Affects the Coordination Number but Not Necessarily the Affinity for Anions of Tris-Bidentate Europium Complexes. Inorg Chem 2020; 59:4096-4108. [PMID: 32105456 DOI: 10.1021/acs.inorgchem.0c00137] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
To evaluate the effect of ligand geometry on the coordination number, number of inner-sphere water molecules, and affinity for anions of the corresponding lanthanide complex, six tris-bidentate 1,2-hydroxypyridonate (HOPO) europium(III) complexes with different cap sizes were synthesized and characterized. Wider or more flexible ligand caps, such as in EuIII-TREN-Gly-HOPO and EuIII-3,3-Gly-HOPO, enable the formation of nine-coordinate europium(III) complexes bearing three inner-sphere water molecules. In contrast, smaller or more rigid caps, such as in EuIII-TREN-HOPO, EuIII-2,2-Li-HOPO, EuIII-3,3-Li-HOPO, and EuIII-2,2-Gly-HOPO, favor eight-coordinate europium(III) complexes that have only two inner-sphere water molecules. Notably, there is no correlation between the number of inner-sphere water molecules and the affinity of the Eu(III) complexes for phosphate. Some q = 2 (EuIII-TREN-HOPO, EuIII-3,3-Li-HOPO, and EuIII-2,2-Gly-HOPO) and some q = 3 (EuIII-TREN-Gly-HOPO) complexes have no affinity for anions, whereas one q = 2 complex (EuIII-2,2-Li-HOPO) and one q = 3 complex (EuIII-3,3-Gly-HOPO) have a high affinity for phosphate. For the latter two systems, each inner-sphere water molecule is replaced with a phosphate anion, resulting in the formation of EuLPi2 and EuLPi3 adducts, respectively.
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Affiliation(s)
- Sheng-Yin Huang
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Michelle Qian
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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16
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Ramakrishnam Raju MV, Harris SM, Pierre VC. Design and applications of metal-based molecular receptors and probes for inorganic phosphate. Chem Soc Rev 2020; 49:1090-1108. [PMID: 32016270 DOI: 10.1039/c9cs00543a] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Inorganic phosphate has numerous biomedical functions. Regulated primarily by the kidneys, phosphate reaches abnormally high blood levels in patients with advanced renal diseases. Since phosphate cannot be efficiently removed by dialysis, the resulting hyperphosphatemia leads to increased mortality. Phosphate is also an important component of the environmental chemistry of surface water. Although required to secure our food supply, inorganic phosphate is also linked to eutrophication and the spread of algal blooms with an increasing economic and environmental burden. Key to resolving both of these issues is the development of accurate probes and molecular receptors for inorganic phosphate. Yet, quantifying phosphate in complex aqueous media remains challenging, as is the development of supramolecular receptors that have adequate sensitivity and selectivity for use in either blood or surface waters. Metal-based receptors are particularly well-suited for these applications as they can overcome the high hydration enthalpy of phosphate that limits the effectiveness of many organic receptors in water. Three different strategies are most commonly employed with inorganic receptors for anions: metal extrusion assays, responsive molecular receptors, and indicator displacement assays. In this review, the requirements for molecular receptors and probes for environmental applications are outlined. The different strategies deployed to recognize and sense phosphate with metal ions will be detailed, and their advantages and shortfalls will be delineated with key examples from the literature.
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Affiliation(s)
| | - Sarah M Harris
- Department of Chemistry, Benedictine College, Atchison, KS 66002, USA
| | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.
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