Lanthanide Complexes as Paramagnetic Probes for ¹⁹F Magnetic Resonance

TLDR

Lanthanide complexes that produce a single major resonance in solution, with the Ln³⁺ ion positioned about 6 Å from the ¹⁹F label, are described. The study reviews the physicochemical basis for designing ¹⁹F MRS and MRI probes. The probes exploit pseudocontact shifts to amplify chemical‑shift non‑equivalence, enabling pH monitoring between 5 and 8. Longitudinal‑relaxation enhancement yields a 15‑fold sensitivity increase in both imaging and spectroscopy.

Abstract

Abstract The physicochemical basis of probe design for 19 F MRS and MRI applications is reviewed. Complexes that give a single major resonance in solution are described, in which the Ln 3+ ion is about 6 Å from the 19 F label. Sensitivity improvements of 15‐fold are reported in both imaging and spectroscopy based on longitudinal relaxation enhancement. The pseudocontact shift allows an amplification of chemical shift non‐equivalence in responsive 19 F probes, e.g. for monitoring pH in the range between 5 and 8.