2026-09-19T15:57:52Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/397402022-01-13T07:54:21Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023
Troy Van Voorhis.
Lu, Aiyan
Massachusetts Institute of Technology. Dept. of Chemistry.
Massachusetts Institute of Technology. Department of Chemistry
2007-12-07T16:16:43Z
2007-12-07T16:16:43Z
2007
2007
http://hdl.handle.net/1721.1/39740
181375821
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2007.
Includes bibliographical references (leaves 30-33).
We present ab initio molecular calculations at different levels of density functional theory (DFT) for the spiro-biphenalenyl neurtral radical in its singlet and triplet states. We performed calculations on the dimer to study its conductivity by investigating the ground state energy, HOMO-LUMO gap, charge localization, and reorganization energies, as these are the main contributing factors to crystal conduction. We find that there is only a slight difference between the singlet state and triplet state HOMO-LUMO gaps. In addition, the negative charge spreads throughout both the interior and exterior units of the molecule in both the singlet state and the triplet state, this is in disagreement with the original argument that the conducting diamagnetic state is a result of the migration of the unpaired electrons to the interior units of the molecule. Finally, we find that the triplet state has higher reorganization energy than that of the singlet. Thus, if conduction were assumed to proceed via a hopping mechanism, the experimental observations would be explained.
by Aiyan Lu.
S.M.
33 leaves
eng
Massachusetts Institute of Technology
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.
http://dspace.mit.edu/handle/1721.1/7582
Chemistry.
Density functional theory study of the conductivity of the biphenalenyl radical dimer
DFT study of the conductivity of the biphenalenyl radical dimer
Thesis
application/pdf
false
Publication
unknown
unknown
<Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="6dd07d7b-ccc3-4da5-b50d-8da8785c99a3">
<Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type>
<Language>eng</Language>
<Title>Density functional theory study of the conductivity of the biphenalenyl radical dimer</Title>
<Subtitle>DFT study of the conductivity of the biphenalenyl radical dimer</Subtitle>
<PublishedIn>
<Publication>
</Publication>
</PublishedIn>
<PublicationDate>2007</PublicationDate>
<Authors>
<Author>
<DisplayName>Lu, Aiyan</DisplayName>
<Affiliation>
<OrgUnit>
</OrgUnit>
</Affiliation>
</Author>
</Authors>
<Editors>
</Editors>
<Publishers>
<Publisher>
<DisplayName>Massachusetts Institute of Technology</DisplayName>
<OrgUnit />
</Publisher>
</Publishers>
<License>http://dspace.mit.edu/handle/1721.1/7582</License>
<Keyword>Chemistry.</Keyword>
<Abstract>We present ab initio molecular calculations at different levels of density functional theory (DFT) for the spiro-biphenalenyl neurtral radical in its singlet and triplet states. We performed calculations on the dimer to study its conductivity by investigating the ground state energy, HOMO-LUMO gap, charge localization, and reorganization energies, as these are the main contributing factors to crystal conduction. We find that there is only a slight difference between the singlet state and triplet state HOMO-LUMO gaps. In addition, the negative charge spreads throughout both the interior and exterior units of the molecule in both the singlet state and the triplet state, this is in disagreement with the original argument that the conducting diamagnetic state is a result of the migration of the unpaired electrons to the interior units of the molecule. Finally, we find that the triplet state has higher reorganization energy than that of the singlet. Thus, if conduction were assumed to proceed via a hopping mechanism, the experimental observations would be explained.</Abstract>
<Access xmlns="http://purl.org/coar/access_right"
>
</Access>
</Publication>