Instant conformational picture in the ab initio simulation of the complex between the Gd(III)cation (green) and the macrocyclic ligand HP-DO3A, exhibiting tertiary amines (blue) and carboxylate et hydroxyle groups (red), with water molecules of the first solvation shells.
The solvation dynamics of complexed metal cations, like liganded gadolinium Gd(III), used as contrast agents in Magnetic resonance Imaging, controls the contrast observed in the MRI images. In this context, the simulation at the molecular level of the dynamical behavior of these species and of their environment (in solution) is crucial for the understanding of the phenomena involved.
The ab initio (Car & Parrinello) molecular dynamics tools have been recently implemented among the theoretical methods of the group having in mind specifically the modelling of lanthanide species. With the simulation of the Gd (III) cation in solution (Yazyev & Helm) en 2006, we have been among the first groups to develop these reseach lines, namely through the study of Gd (III) complexed with HP-DO3A, a chelating agent of low molecular weight.