Kinetically Inert Macrocyclic Europium(III) Receptors for Phosphate

Overview

Journal Inorg Chem

Specialty Chemistry

Date 2023 Jun 20

PMID 37339454

Authors

Thibaut L M Martinon

Mandapati V Ramakrishnam Raju

Valerie C Pierre

Affiliations

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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 Eu-TACD-HOPO in water was insufficient for luminescent studies. Whereas Eu-cyclen-HOPO is eight coordinate with two inner-sphere water molecules, both Eu-cyclam-HOPO and Eu-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, Eu-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 Eu-TACN-HOPO and Eu-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. Eu-cyclen-HOPO and, to a lesser extent, Eu-TACN-HOPO are more kinetically inert than the linear Eu-Ser-HOPO. Eu-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.

References

Werner E, Avedano S, Botta M, Hay B, Moore E, Aime S . Highly soluble tris-hydroxypyridonate Gd(III) complexes with increased hydration number, fast water exchange, slow electronic relaxation, and high relaxivity. J Am Chem Soc. 2007; 129(7):1870-1. PMC: 3188311. DOI: 10.1021/ja068026z. View

Bhargava R, Kalra P, Hann M, Brenchley P, Hurst H, Hutchison A . A randomized controlled trial of different serum phosphate ranges in subjects on hemodialysis. BMC Nephrol. 2019; 20(1):37. PMC: 6360717. DOI: 10.1186/s12882-019-1216-2. View

Lee H, Swamy K, Kim S, Kwon J, Kim Y, Kim S . Simple but effective way to sense pyrophosphate and inorganic phosphate by fluorescence changes. Org Lett. 2007; 9(2):243-6. DOI: 10.1021/ol062685z. View

Eustace J, Astor B, Muntner P, Ikizler T, Coresh J . Prevalence of acidosis and inflammation and their association with low serum albumin in chronic kidney disease. Kidney Int. 2004; 65(3):1031-40. DOI: 10.1111/j.1523-1755.2004.00481.x. View

Pierre V, Botta M, Aime S, Raymond K . Substituent effects on Gd(III)-based MRI contrast agents: optimizing the stability and selectivity of the complex and the number of coordinated water molecules. Inorg Chem. 2006; 45(20):8355-64. PMC: 3190981. DOI: 10.1021/ic061262q. View

Huang S, Pierre V . Achieving Selectivity for Phosphate over Pyrophosphate in Ethanol with Iron(III)-Based Fluorescent Probes. JACS Au. 2022; 2(7):1604-1609. PMC: 9326827. DOI: 10.1021/jacsau.2c00200. View

Arnedo-Sanchez L, Smith K, Deblonde G, Carter K, Moreau L, Rees J . 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(3):483-491. DOI: 10.1002/cplu.202100083. View

Pierre V, Botta M, Aime S, Raymond K . Tuning the coordination number of hydroxypyridonate-based gadolinium complexes: implications for MRI contrast agents. J Am Chem Soc. 2006; 128(16):5344-5. PMC: 3188315. DOI: 10.1021/ja057805x. View

Cupisti A, Gallieni M, Rizzo M, Caria S, Meola M, Bolasco P . Phosphate control in dialysis. Int J Nephrol Renovasc Dis. 2013; 6:193-205. PMC: 3797240. DOI: 10.2147/IJNRD.S35632. View

10.

Thordarson P . Determining association constants from titration experiments in supramolecular chemistry. Chem Soc Rev. 2010; 40(3):1305-23. DOI: 10.1039/c0cs00062k. View

11.

Jordan J, Ashbaugh H, Mague J, Gibb B . Buffer and Salt Effects in Aqueous Host-Guest Systems: Screening, Competitive Binding, or Both?. J Am Chem Soc. 2021; 143(44):18605-18616. PMC: 8587612. DOI: 10.1021/jacs.1c08457. View

12.

Wilharm R, Huang S, Gugger I, Pierre V . 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(20):15808-15817. PMC: 8900436. DOI: 10.1021/acs.inorgchem.1c02462. View

13.

Radbruch A, Richter H, Fingerhut S, Martin L, Xia A, Henze N . Gadolinium Deposition in the Brain in a Large Animal Model: Comparison of Linear and Macrocyclic Gadolinium-Based Contrast Agents. Invest Radiol. 2019; 54(9):531-536. DOI: 10.1097/RLI.0000000000000575. View

14.

Harris S, Nguyen J, Pailloux S, Mansergh J, Dresel M, Swanholm T . Gadolinium Complex for the Catch and Release of Phosphate from Water. Environ Sci Technol. 2017; 51(8):4549-4558. DOI: 10.1021/acs.est.6b05815. View

15.

Huang S, Qian M, Pierre V . A Combination of Factors: Tuning the Affinity of Europium Receptors for Phosphate in Water. Inorg Chem. 2019; 58(23):16087-16099. DOI: 10.1021/acs.inorgchem.9b02650. View

16.

Caravan P, Ellison J, McMurry T, Lauffer R . Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications. Chem Rev. 2001; 99(9):2293-352. DOI: 10.1021/cr980440x. View

17.

Martinon T, Pierre V . Luminescent Lanthanide Probes for Inorganic and Organic Phosphates. Chem Asian J. 2022; 17(16):e202200495. PMC: 9388549. DOI: 10.1002/asia.202200495. View

18.

Cacheris W, Quay S, Rocklage S . The relationship between thermodynamics and the toxicity of gadolinium complexes. Magn Reson Imaging. 1990; 8(4):467-81. DOI: 10.1016/0730-725x(90)90055-7. View

19.

Di Gregorio E, Lattuada L, Maiocchi A, Aime S, Ferrauto G, Gianolio E . Supramolecular adducts between macrocyclic Gd(iii) complexes and polyaromatic systems: a route to enhance the relaxivity through the formation of hydrophobic interactions. Chem Sci. 2021; 12(4):1368-1377. PMC: 8179163. DOI: 10.1039/d0sc03504a. View

20.

Pierre V, Wilharm R . Design Principles and Applications of Selective Lanthanide-Based Receptors for Inorganic Phosphate. Front Chem. 2022; 10:821020. PMC: 8859545. DOI: 10.3389/fchem.2022.821020. View