Elucidating polyphosphate anion binding to lanthanide complexes using EXAFS and pulsed EPR Spectroscopy

DOI: 10.1021/acs.inorgchem.4c03399

Authors: Hannah K. Pyle (Loughborough University) , Martyna Judd (The Australian National University Canberra) , Anthony Barancewicz (The Australian National University Canberra) , Alexander J. Mayer (Loughborough University) , Nicholas Cox (The Australian National University Canberra) , Simon A. Kondrat (Loughborough University) , Stephen J. Butler (Loughborough University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Inorganic Chemistry

State: Published (Approved)
Published: October 2024
Diamond Proposal Number(s): 29024

Abstract: Reversible anion binding to lanthanide complexes in aqueous solution has emerged as an effective method for anion sensing. Through careful design of the organic ligand, luminescent lanthanide complexes capable of binding biologically relevant anions in a bidentate or monodentate manner can be realized. While single-crystal X-ray diffraction analyses and NMR spectroscopy have revealed the structural geometry of several host–guest complexes, the challenge remains in designing preorganized lanthanide receptors with enhanced anion selectivity for broader applications in diagnostics and bioimaging. To address this challenge, innovative and complementary methods to investigate host-anion binding geometry are becoming increasingly important. Herein, we demonstrate the combined use of Eu L3-edge extended X-ray absorption fine structure (EXAFS) and electron paramagnetic resonance (EPR) spectroscopy to elucidate the binding of nucleoside phosphates (ATP, ADP, and AMP) to a cationic lanthanide complex. We establish that ATP unequivocally binds the lanthanide center in a bidentate manner in water, while ADP adopts both bidentate and monodentate modes, and AMP binds in a monodentate manner. This interdisciplinary approach provides deeper insight into lanthanide host–guest chemistry in solution, laying the groundwork for designing emissive probes that undergo specific anion-induced structural changes and elicit desired optical responses upon binding.

Subject Areas: Chemistry


Instruments: I20-Scanning-X-ray spectroscopy (XAS/XES)

Added On: 17/10/2024 10:11

Documents:
pyle-et-al-2024-elucidating-polyphosphate-anion-binding-to-lanthanide-complexes-using-exafs-and-pulsed-epr-spectroscopy.pdf

Discipline Tags:

Molecular Complexes Chemistry Inorganic Chemistry

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS)