Computational chemical analysis of Eu(iii) and Am(iii) complexes with pnictogen-donor ligands using DFT calculationsElectronic supplementary information (ESI) available: Total energies and Gibbs correction energies for all compounds and Cartesian coordinates of calculated geometries and MO energy data with partial density of states of metal ions and overlap population between the metal ion and the donor atoms in the valence region for [M(DMXE)(H2O)6]3+. See DOI: 10.1039/c8dt01973h

• Main Authors: Kimura, Taiki, Kaneko, Masashi, Watanabe, Masayuki, Miyashita, Sunao, Nakashima, Satoru
• Format: Journal Article
• Published: 30.10.2018
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt01973h

We demonstrated density functional calculations of Eu( iii ) and Am( iii ) complexes with pnictogen-donor (X) ligands, (CH 3 ) 2 X-CH 2 -CH 2 -X(CH 3 ) 2 (X = N, P, As and Sb). We investigated the optimized structures of the complexes and the Gibbs energy differences in the complex formation reactions. The results indicated that the N- and P-donor ligands exhibit Am( iii ) ion selectivity over Eu( iii ) ions; especially, the P-donor ligand showed the highest selectivity. The tendency of the Am( iii )/Eu( iii ) selectivity by the pnictogen-donor ligands was found to be comparable to that of the soft acid classification in the hard and soft acids and bases rule. Mulliken's spin population analysis indicated that the bonding properties between the metal ion and the pnictogen atoms correlated with the Am( iii )/Eu( iii ) selectivity. In particular, the participation of f-orbital electrons of the metal ion in the covalency was indicated to play an important role in the selectivity. High selectivity of a P-donor ligand for Am( iii ) over Eu( iii ) is comparable to the soft acid classification of the HSAB rule and can be correlated with the covalency in f-orbital type MO surfaces.