Presentation Title

Energy Calculations on Fluorinated DIPAB Derivatives

Faculty Mentor

Kimberley Cousins

Start Date

17-11-2018 12:30 PM

End Date

17-11-2018 2:30 PM

Location

CREVELING 15

Session

POSTER 2

Type of Presentation

Poster

Subject Area

physical_mathematical_sciences

Abstract

Molecular ferroelectrics have the ability to maintain polarization, as well as reverse polarization in an electric field. As an effective way to calculate the stability of fluorinated derivatives of diisopropylammonium bromide(DIPAB) we have used Spartan’16 a computer program that allows access to calculations of derivatives that have not yet been made or studied. DIPAB is a molecular crystal with piezoelectric and ferroelectric properties. First, a basis set study was performed using the functionals wB97X-D and EDF2 and the basis set chosen was 6-311+G(2df,2p) to provide the most stable energy for the DIPAB dimer in a reasonable amount of time. As a molecular part in the derivative, two systems were created, with the nitrogen atom of each having different hydrogen atoms removed, starting from the crystal structure confirmation. For system 1, the hydrogen farthest from the bromine atom was removed; for system 2, the hydrogen closest to the bromine atom was removed. Then, fluorine atoms were used to replace hydrogen atoms on the isopropyl groups (C-H to C-F). We observed that the amount of fluorine makes a difference in the reaction energies, calculated using Hess’ Law, with more fluorine atoms, the higher energy, and therefore, higher instability. We then observed a trend between symmetrical molecules versus asymmetrical molecules. Symmetrical molecules, with a higher amount of fluorine, had the highest instability, while asymmetrical molecules have greater stability. We repeated these vacuum phase calculations in water using Spartan’ 16 to simulate the polar crystal environment and we saw similar trends.

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Nov 17th, 12:30 PM Nov 17th, 2:30 PM

Energy Calculations on Fluorinated DIPAB Derivatives

CREVELING 15

Molecular ferroelectrics have the ability to maintain polarization, as well as reverse polarization in an electric field. As an effective way to calculate the stability of fluorinated derivatives of diisopropylammonium bromide(DIPAB) we have used Spartan’16 a computer program that allows access to calculations of derivatives that have not yet been made or studied. DIPAB is a molecular crystal with piezoelectric and ferroelectric properties. First, a basis set study was performed using the functionals wB97X-D and EDF2 and the basis set chosen was 6-311+G(2df,2p) to provide the most stable energy for the DIPAB dimer in a reasonable amount of time. As a molecular part in the derivative, two systems were created, with the nitrogen atom of each having different hydrogen atoms removed, starting from the crystal structure confirmation. For system 1, the hydrogen farthest from the bromine atom was removed; for system 2, the hydrogen closest to the bromine atom was removed. Then, fluorine atoms were used to replace hydrogen atoms on the isopropyl groups (C-H to C-F). We observed that the amount of fluorine makes a difference in the reaction energies, calculated using Hess’ Law, with more fluorine atoms, the higher energy, and therefore, higher instability. We then observed a trend between symmetrical molecules versus asymmetrical molecules. Symmetrical molecules, with a higher amount of fluorine, had the highest instability, while asymmetrical molecules have greater stability. We repeated these vacuum phase calculations in water using Spartan’ 16 to simulate the polar crystal environment and we saw similar trends.