Presentation Title

Interactions between electric, ferroelectric, and non-ferroelectric dimers

Start Date

November 2016

End Date

November 2016

Location

HUB 302-7

Type of Presentation

Poster

Abstract

Ferroelectricity has a spontaneous electric polarization that can be reversed by the application of an external field. Ferroelectric materials can be used to make, for example, capacitors with tunable capacitance. Organic electronic ferroelectrics are organic molecules that form charge transfer dimers in the solid state when treated with an applied voltage. In this study, SPARTAN'10 calculated energies of association were used to examine if dimer energy correlated with electron transfer would be reliable for screening new organic ferroelectrics. Potential charge transfer pairs, including chloranil/tetrathiofulvene (CA/TTF) were extracted from known crystal structures, maintaining the original geometries. From this experiment it was discovered that basis sets larger than Hartree Fock (HF), 6-31G* are needed to properly measure this charge transfer, and corresponding energetic advantage. At the HF 6-31G* level, calculated steric repulsion is greater than any energy advantage due to attraction generated by charge transfer. Using larger basis sets, we saw that when the dimers of chloranil/ tetrathiofulvalene are closer together they show greater charge transfer and a more stable dimer. This indicates that SPARTAN-generated energies calculated using larger basis sets could be used as a potential source for screening new organic ferroelectrics.

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Nov 12th, 1:00 PM Nov 12th, 2:00 PM

Interactions between electric, ferroelectric, and non-ferroelectric dimers

HUB 302-7

Ferroelectricity has a spontaneous electric polarization that can be reversed by the application of an external field. Ferroelectric materials can be used to make, for example, capacitors with tunable capacitance. Organic electronic ferroelectrics are organic molecules that form charge transfer dimers in the solid state when treated with an applied voltage. In this study, SPARTAN'10 calculated energies of association were used to examine if dimer energy correlated with electron transfer would be reliable for screening new organic ferroelectrics. Potential charge transfer pairs, including chloranil/tetrathiofulvene (CA/TTF) were extracted from known crystal structures, maintaining the original geometries. From this experiment it was discovered that basis sets larger than Hartree Fock (HF), 6-31G* are needed to properly measure this charge transfer, and corresponding energetic advantage. At the HF 6-31G* level, calculated steric repulsion is greater than any energy advantage due to attraction generated by charge transfer. Using larger basis sets, we saw that when the dimers of chloranil/ tetrathiofulvalene are closer together they show greater charge transfer and a more stable dimer. This indicates that SPARTAN-generated energies calculated using larger basis sets could be used as a potential source for screening new organic ferroelectrics.