Understanding the complexation of lanthanide (Ln) and actinide (An) trications in liquid water represent a challenging topic in nuclear waste retreatment. Here we focus our attention on such complexes of interest in geological media, like carbonates and silicates. Starting from the polarizable Ln3+ - and An3+- water force field developed recently in our group [1], from which we were able to explain structural, thermodynamical and transport properties [2], we have initially developed polarizable and non-polarizable force fields for La3+ from ab initio calculations [3]. Calculations at different levels show that, in vacuum and in liquid phase, La3+ ions are energetically more stable when complexed with three carbonates than with four. We will show results on structural and thermodynamical properties with a particular consideration on how explicit water molecules can enter (or not) in the La first shell. Finally, we will show how, starting from monodentate structures, they collapse in the bidentate ones overpassing a torsional energetic barrier.Our extrapolation procedure to obtain force field for other systems allowed us to predict structure and thermodynamics for all the lanthanides/carbonates complexes. The recent validation of the hypotheses about the chemical equivalence between the lanthanoids and the actinides 3+ ions in interaction with water [4] allows us to study the An3+ series without performing expensive quantum chemistry calculations for all the atoms and obtaining reliable results. 1) Duvail et al. J. Chem. Phys. 2009, 130, 104501; Duvail et al. J. Chem. Phys. 2011, 135, 044503.2) D'Angelo et al. Inorg. Chem. 2011, 50, 4572� 4579; Martelli et al. J. Chem. Phys. 2012, in press.3) Jeanvoine et al. Phys. Chem. Chem Phys. in press DOI:10.1039/C2CP41996C4) P.D'Angelo and R.Spezia. Chem. Eur. J. 2012, 18, 11162 - 11178.

Structural and thermodynamical properties of lanthanide and actinides complexes in liquid water from molecular dynamics simulations

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.