Extraction of Strontium(ii) by Crown Ether: Insights From Density Functional Calculation

Abstract

The structures, energetic and thermodynamic parameters of crown ethers with different cavity size, electron donating/withdrawing substituent groups and donor atoms have been determined with density functional method at B3LYP level of theory in gas and solvent phase. Small core quasi-relativistic effective core potentials was used together with the accompanying SDD basis set for Sr2+ and DZP basis set was used for crown ether atoms. Natural bond orbital (NBO) analysis was evaluated to characterize the distribution of electrons on the complexes. The interaction energy is well correlated with the values of Strontium charge after complexation, the second order interaction energies (E2) and HOMO-LUMO energy gab (∆Egab). The interaction energy and thermodynamics parameters in gas phase are reduced in solvent phase as the solvent molecules weaken the metal-crown ether interaction. The thermodynamic parameters indicated that less feasibility to extract Sr2+ ion directly from pure water without presence of organic solvent. The theoretical values of extraction energy for Sr(NO3)2 salt from aqueous solution in different organic solvent is validated by the experimental trend. This study would have strong contribution in planning the experiments to the design of specific host ligand and screening of solvent for extraction of metal ion.

Theoretical Study on the Extraction of Alkaline Earth Salts by 18-Crown-6: Roles of Counterions, Solvent Types and Extraction Temperatures

“…The extraction of Sr(NO 3 ) 2 salt with 18-membered crown ethers in biphasic solvent has been studied using DFT method at B3LYP level of theory using SDD and DZP basis sets. The extraction energies from biphasic systems showed linear trend with the experimental stability constant [19].…”

Use of Polymer Membranes for Modeling Desulfurization in the Process of Pervaporation through Artificial Neural Network

“…Corrosion dominantly occurs in the solution, therefore solvent effects were included using the PCM as implemented in the default Gaussian code using a dielectric constant of 78.4 for water. Structure reoptimizations in the presence of the solvent were found to have a minor influence on energetics (Hadisaputra et al, 2012(Hadisaputra et al, , 2014b(Hadisaputra et al, , 2014a. Therefore, the single-point approach has been employed in this study, as it allows computational costs to be minimized without sacrificing much accuracy in solvation energies.…”

A combined experimental and theoretical study of (E)-ethyl 3-(4-methoxyphenyl)acrylate as corrosion inhibitor of iron in 1 M HCl solutions

“…The polarized continuum model (PCM) was used to calculate the solvent effects due to corrosion dominantly occurred in the aqueous environment. To determine the energy of the interaction, the re-optimization of the structure was not performed on the solvent because it had little effect on the energetic so that it was sufficient to use single-point calculations on gas-phase geometries [17][18][19][20]. All theoretical calculations are performed with the Gaussian 03 package [21].…”