10.1021/ic7016616.s002
Ivelina Georgieva
Natasha Trendafilova
Adélia J. A. Aquino
Hans Lischka
Theoretical Study of Metal−Ligand Interaction in Sm(III), Eu(III), and
Tb(III) Complexes of Coumarin-3-Carboxylic Acid in the Gas Phase and
Solution
2007
American Chemical Society
energy partitioning analysis
continuum solvation model
Gas Phase
SolutionThe interaction
carboxylate moiety
interaction term
population analyses
interaction terms
ligand deformation energies
deprotonated form
Solvent effects
binding energies
covalent contributions
water clusters
CCSD
covalent contribution
Theoretical Study
DFT
reference MP 2
Ln
energy decomposition calculations
electron distribution analysis
2007-12-10 00:00:00
article
https://acs.figshare.com/articles/journal_contribution/Theoretical_Study_of_Metal_Ligand_Interaction_in_Sm_III_Eu_III_and_Tb_III_Complexes_of_Coumarin_3_Carboxylic_Acid_in_the_Gas_Phase_and_Solution/2969830
The interaction of lanthanide(III) cations (Ln(III) = Sm(III), Eu(III), and Tb(III)) with the deprotonated form of the
coumarin-3-carboxylic acid (<i>cca</i><i><sup>-</sup></i><sup></sup>) has been investigated by density functional theory (DFT/B3LYP) and confirmed
by reference MP2 and CCSD(T) computations. Solvent effects on the geometries and stabilities of the Ln(III)
complexes were computed using a combination of water clusters and a continuum solvation model. The following
two series of systems were considered: (i) Ln(<i>cca</i>)<sup>2+</sup>, Ln(<i>cca</i>)<sub>2</sub><sup>+</sup>, Ln(<i>cca</i>)<sub>3</sub> and (ii) Ln(<i>cca</i>)(H<sub>2</sub>O)<sub>2</sub>Cl<sub>2</sub>, Ln(<i>cca</i>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>Cl, Ln(<i>cca</i>)<sub>3</sub>. The strength and character of the Ln(III)−<i>cca</i><i><sup>-</sup></i><sup></sup> bidentate bonding were characterized by calculated
Ln−O bond lengths, binding energies, ligand deformation energies, energy partitioning analysis, σ-donation
contributions, and natural population analyses. The energy decomposition calculations predicted predominant
electrostatic interaction terms to the Ln−<i>cca</i> bonding (ionic character) and showed variations of the orbital interaction
term (covalent contributions) for the Ln−<i>cca</i> complexes studied. Electron distribution analysis suggested that the
covalent contribution comes mainly from the interaction with the carboxylate moiety of <i>cca</i><sup>-</sup>.