Harnessing chemical exchange: 19F magnetic resonance OFF/ON zinc sensing with a Tm(iii) complex

Meng Yu; Da Xie; Rahul T Kadakia; Weiran Wang; Emily L Que

doi:10.1039/d0cc01876g

Harnessing chemical exchange: ¹⁹F magnetic resonance OFF/ON zinc sensing with a Tm(iii) complex

Chem Commun (Camb). 2020 Jun 11;56(46):6257-6260. doi: 10.1039/d0cc01876g. Epub 2020 May 6.

Authors

Meng Yu¹, Da Xie, Rahul T Kadakia, Weiran Wang, Emily L Que

Affiliation

¹ Department of Chemistry, The University of Texas at Austin, 105 E. 24th St Stop A5300, Austin, Texas 78712, USA. emilyque@cm.utexas.edu.

PMID: 32373870
DOI: 10.1039/d0cc01876g

Abstract

A fluorinated, thulium(iii) complex (Tm-PFZ-1) serves as an off-on ¹⁹F magnetic resonance probe for Zn(ii). Rapid exchange among different conformations combined with paramagnetic relaxation and chemical shift effects of Tm(iii) effectively eliminate the ¹⁹F NMR/MRI signal in Tm-PFZ-1. Chelation of Zn(ii) induces increased structural rigidity and reduces exchange rate, affording a robust ¹⁹F NMR/MRI signal. Tm-PFZ-1 represents a first-in-class paramagnetic ¹⁹F MR agent that exploits a novel sensing mechanism for Zn(ii) and is the first ¹⁹F MR-based scaffold to provide an "off-on" response to Zn(ii) in aqueous solution.