The complexation of calcium(II) and lanthanide(III) cations with the phosphate substitute (carboxymethoxy)succinate (CMOS), as studied by magnetic resonance spectroscopy

Abstract

AbstractThe complexation of trisodium (carboxymethoxy)succinate (Na3CMOS) with calcium(II) and with lanthanide(III) cations has been studied using NMR spectroscopy. Structural information has been obtained from lanthanide‐induced shifts (LIS), T1 relaxation rate enhancements and vicinal 1H coupling constants. CMOS forms 1:1 and 1:2 complexes in which it mainly acts as a tetradentate ligand via the three carboxylate groups and the ether oxygen. LIS measurements on non‐racemic mixtures of Na3CMOS indicate self‐association of the Ln(III) complexes at [CMOS]0 > 0.01 M.