Enhancing ³¹P NMR relaxation rates with a kinetically inert gadolinium complex

Abstract

The heptadentate gadolinium complex Gd.pDO3A (1.Gd) generates significant 31P nuclear magnetic resonance (NMR) relaxation enhancement of biologically relevant phosphate species; adenosine triphosphate (ATP), phosphocreatine (PCr) and inorganic phosphate.

Chelating chloride using binuclear lanthanide complexes in water

“…These results could be suggestive of competitive binding of phosphate: indeed, the changes to the form of the spectra in phosphate buffer (in comparison with the spectra in water) are strongly suggestive of phosphate binding in line with other mono and binuclear lanthanide complexes derived from DO3A. 4,31,37…”

“…These results could be suggestive of competitive binding of phosphate: indeed, the changes to the form of the spectra in phosphate buffer (in comparison with the spectra in water) are strongly suggestive of phosphate binding in line with other mono and binuclear lanthanide complexes derived from DO3A. 4,31,37 NMR studies of chloride binding at lanthanide centres present difficulties due to the interference of the quadrupolar relaxation from the low symmetry 35 Cl nucleus with the paramagnetic metal centre resulting in broad 1 H and 35 Cl NMR signals. However, dipolar 35 Cl NMR chemical shis induced by the addition of chloride to axially symmetric [Ln(DOTA)] − complexes give well-resolved 35 Cl NMR spectra that can be interpreted as evidence of interaction with chloride.…”

Advances in anion binding and sensing using luminescent lanthanide complexes

“…7b ) has been studied by the Faulkner group using 31 P NMR spectroscopy. 47 Gd( iii ) and Eu( iii ) complexes of a DO3A ligand bearing a single alkyne group were prepared as precursors to more elaborate architectures. It was hypothesised that HPO 4 2− would bind to the neutral complexes ( q = 2) with low affinity and with relatively rapid exchange kinetics, enabling analysis of bulk phosphate species in solution.…”

Tuning the anion binding properties of lanthanide receptors to discriminate nucleoside phosphates in a sensing array

“…In the presence of 5 mM AMP, a q value of 0.3-0.7 was found, indicating partial hydration, possibly reecting the weaker monodentate binding of AMP, in accordance with previous examples of phosphate binding at lanthanide centres. 18,23,25…”

“…This strategy has been utilised to develop receptors for anions including phosphate, [23][24][25] bicarbonate, 26,27 uoride, [28][29][30] and lactate. 31 Such Ln(III) complexes are kinetically stable, avoiding complications arising from metal ion dissociation upon anion binding.…”