TY - JOUR

T1 - The role of covalency in enhancing stability of Eu and Am complexes

T2 - a DFT comparison of BTP and BTPhen †

AU - Fryer-Kanssen, Izaak

AU - Malcomson, Thomas

AU - Austin, Jonathan

AU - Kerridge, Andrew

PY - 2023/8/7

Y1 - 2023/8/7

N2 - We compare the stabilities and bonding nature of [Eu/Am(BTPhen) (NO )] complexes to those previously reported for [Eu/Am(BTP) ] , and investigate whether more accurately reflecting the reaction conditions of the separation process by considering [Eu/Am(NO ) (H O) ] ( = 3, 4) complexes instead of aquo complexes increases the selectivity of the separation ligands BTP and BTPhen for Am over Eu. The geometric and electronic structures of [Eu/Am(BTPhen) (NO )] and [Eu/Am(NO ) (H O) ] ( = 3, 4) have been evaluated using density functional theory (DFT) and used as the basis for analysis of the electron density through the application of the quantum theory of atoms in molecules (QTAIM). Increased covalent bond character for the Am complexes of BTPhen over Eu analogues was found, with this increase more pronounced than that found in BTP complexes. BHLYP-derived exchange reaction energies were evaluated using the hydrated nitrates as a reference and a favourability for actinide complexation by both BTP and BTPhen was found, with the BTPhen ligand found to be more selective, with relative stability ≈0.17 eV greater than BTP.

AB - We compare the stabilities and bonding nature of [Eu/Am(BTPhen) (NO )] complexes to those previously reported for [Eu/Am(BTP) ] , and investigate whether more accurately reflecting the reaction conditions of the separation process by considering [Eu/Am(NO ) (H O) ] ( = 3, 4) complexes instead of aquo complexes increases the selectivity of the separation ligands BTP and BTPhen for Am over Eu. The geometric and electronic structures of [Eu/Am(BTPhen) (NO )] and [Eu/Am(NO ) (H O) ] ( = 3, 4) have been evaluated using density functional theory (DFT) and used as the basis for analysis of the electron density through the application of the quantum theory of atoms in molecules (QTAIM). Increased covalent bond character for the Am complexes of BTPhen over Eu analogues was found, with this increase more pronounced than that found in BTP complexes. BHLYP-derived exchange reaction energies were evaluated using the hydrated nitrates as a reference and a favourability for actinide complexation by both BTP and BTPhen was found, with the BTPhen ligand found to be more selective, with relative stability ≈0.17 eV greater than BTP.

U2 - 10.1039/d3cp01832f

DO - 10.1039/d3cp01832f

M3 - Journal article

VL - 25

SP - 19453

EP - 19461

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 29

ER -