Theoretical study of actinide(III)-DOTA complexes

1,4,7,10-Tetraazacyclododecane-N,N′,N″,N′″-tetraacetic acid (DOTA) is a prominent chelating ligand used in imaging contrast agents and radiopharmaceutics. The present study explores the stability, structure and bonding properties of its complexes with trivalent actinides (Ac, U, Np, Pu, Am, Cm, Cf) using density functional theory and relativistic multireference calculations. For reference purposes, the La- and Lu-DOTA complexes are also included. Similarly to La3+, the large An3+ ions prefer the TSAP conformer of the ligand. The An-ligand bonding is mainly electrostatic, with minor charge transfer contributions to the An 6d orbitals. No participation of 5f orbitals in the bonding was found. For the assessment of the thermodynamic stabilities in aqueous solution, PCM radii to use in conjunction with the SMD solvation model were developed. Basically, the thermodynamic stability of the DOTA complexes increases along the An row, but with notable counteracting of spin-orbit coupling.

KOVACS Attila; 

2021-10-01

AMER CHEMICAL SOC

JRC124370

2470-1343 (online),   

https://doi.org/10.1021/acsomega.1c01292,    https://publications.jrc.ec.europa.eu/repository/handle/JRC124370,   

10.1021/acsomega.1c01292 (online),