Structure and dynamics of all of the stereoisomers of europium complexes of tetra(carboxyethyl) derivatives of dota: ring inversion is decoupled from cooperative arm rotation in the RRRR and RRRS isomers

Abstract
The absolute configuration of the four stereoisomeric α-substituted derivatives of dota has been defined; in their Eu complexes, 2D-NMR methods have revealed that in solution ring inversion is independent of pendant arm rotation and the (RRRR)-[EuL1a] complex which in the solid state crystallises as a square antiprismatic structure.