Solvation Shell and Ion Pair Species Geometries and Energetics of Magnesium and Zinc Ions

Project Information

computational-chemistry, gaussian, molecular-dynamics
Project Status: Recruiting
Project Region: Kentucky
Submitted By: Vikram Gazula
Project Email: kristen.fulfer@centre.edu
Project Institution: Centre College
Anchor Institution: KY-University of Kentucky
Project Address: Danville, Kentucky. 40422

Mentors: Recruiting
Students: Recruiting

Project Description

Our group is a mainly experimental physical chemistry group at Centre College, which utilizes computational chemistry to complement and provide further insight into experimental results. Our main interest currently is investigating solution structure of electrolytes composed of either magnesium or zinc salts in non-aqueous solvents. The magnesium ion solutions have potential applications in the portable energy storage industry, as magnesium ion batteries are being investigated as potential replacements, or at the least complements, to lithium ion batteries. This is due in part to the large availability (and thus low cost) of magnesium. Due to the bivalent charge of magnesium ions, they are also likely to be more efficient charge carriers within an electrolyte solution than the monovalent lithium ion. While zinc ions are not being currently investigated by the portable energy storage industry, we want to study zinc and magnesium based electrolytes side-by-side, since magnesium and zinc bivalent ions have identical Shannon radii, though very different chemical properties based on their placement within the periodic table. This side-by-side comparison may provide insight into which properties (physical or chemical) play the larger role in determining molecular-level electrolyte structure and thus bulk electrolyte properties. One issue that has arisen in the portable energy storage industry is a lack of understanding of molecular level structure within the electrolytes and the role of these structures on macroscopic properties. Our group uses infrared spectroscopy and computational chemistry to determine the molecular level solution structure of various electrolytes. Experimentally, we measure the spectral signatures which arise from either the solvent or the anion and observe how these signatures are affected by various parameters, including concentration. Using primarily density functional theory computations, we can try to correlate molecular level changes in solution structure to changes in spectral signatures.


Optimize the geometry of several possible solvation shells of each cation (Mg and Zn) with tetramethylurea and compare the energy and predicted IR frequencies of each complex to compare with experimental IR spectra. Quantify the interaction energy between the cation and each tetramethylurea solvent molecule in the primary solvation sheath of the cation. Perform an optimization and interaction energy calculation for each cation interacting with a variety of different non-aqueous solvents to find other likely compatible solvents, based on similarities in cation-solvent interaction energy. Optimize the geometry of several possible solvation shells of each cation with the most likely solvents from the solvent compatibility search to compare likely solvation shell geometries. Optimize the geometry of several possible ionic and ion-paired species involving both the cation (Mg or Zn ions) and various anions and compare the energy and predicted IR frequencies of each complex to compare with experimental IR spectra.

Project Information

computational-chemistry, gaussian, molecular-dynamics
Project Status: Recruiting
Project Region: Kentucky
Submitted By: Vikram Gazula
Project Email: kristen.fulfer@centre.edu
Project Institution: Centre College
Anchor Institution: KY-University of Kentucky
Project Address: Danville, Kentucky. 40422

Mentors: Recruiting
Students: Recruiting

Project Description

Our group is a mainly experimental physical chemistry group at Centre College, which utilizes computational chemistry to complement and provide further insight into experimental results. Our main interest currently is investigating solution structure of electrolytes composed of either magnesium or zinc salts in non-aqueous solvents. The magnesium ion solutions have potential applications in the portable energy storage industry, as magnesium ion batteries are being investigated as potential replacements, or at the least complements, to lithium ion batteries. This is due in part to the large availability (and thus low cost) of magnesium. Due to the bivalent charge of magnesium ions, they are also likely to be more efficient charge carriers within an electrolyte solution than the monovalent lithium ion. While zinc ions are not being currently investigated by the portable energy storage industry, we want to study zinc and magnesium based electrolytes side-by-side, since magnesium and zinc bivalent ions have identical Shannon radii, though very different chemical properties based on their placement within the periodic table. This side-by-side comparison may provide insight into which properties (physical or chemical) play the larger role in determining molecular-level electrolyte structure and thus bulk electrolyte properties. One issue that has arisen in the portable energy storage industry is a lack of understanding of molecular level structure within the electrolytes and the role of these structures on macroscopic properties. Our group uses infrared spectroscopy and computational chemistry to determine the molecular level solution structure of various electrolytes. Experimentally, we measure the spectral signatures which arise from either the solvent or the anion and observe how these signatures are affected by various parameters, including concentration. Using primarily density functional theory computations, we can try to correlate molecular level changes in solution structure to changes in spectral signatures.


Optimize the geometry of several possible solvation shells of each cation (Mg and Zn) with tetramethylurea and compare the energy and predicted IR frequencies of each complex to compare with experimental IR spectra. Quantify the interaction energy between the cation and each tetramethylurea solvent molecule in the primary solvation sheath of the cation. Perform an optimization and interaction energy calculation for each cation interacting with a variety of different non-aqueous solvents to find other likely compatible solvents, based on similarities in cation-solvent interaction energy. Optimize the geometry of several possible solvation shells of each cation with the most likely solvents from the solvent compatibility search to compare likely solvation shell geometries. Optimize the geometry of several possible ionic and ion-paired species involving both the cation (Mg or Zn ions) and various anions and compare the energy and predicted IR frequencies of each complex to compare with experimental IR spectra.