Crystal Structures of DOTMA Chelates from Ce3+ to Yb3+ : Evidence for a Continuum of Metal Ion Hydration States.

ABSTRACT: The crystal structures of chelates formed between each stable paramagnetic lanthanide ion and the octadentate polyamino carboxylate ligand DOTMA are described. A total of 23 individual chelates structures were obtained; in each chelate the coordination geometry around the metal ion is best described as a twisted square antiprism (torsion angle -25.0°--31.4°). Despite the uniformity of the general coordination geometry provided by the DOTMA ligand, there is a considerable variation in the hydration state of each chelate. The early Ln3+ chelates are associated with a single inner sphere water molecule; the Ln-OH2 interaction is remarkable for being very long. After a clear break at gadolinium, the number of chelates in the unit cell that have a water molecule interacting with the Ln3+ decrea

SUBMITTER: Woods M 

PROVIDER: S-EPMC6700027 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature