• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Two-photon spectroscopy of conjugated organic chromophores

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_3107028_sip1_m.pdf
    Size:
    5.205Mb
    Format:
    PDF
    Download
    Author
    Pond, Stephanie J.
    Issue Date
    2003
    Keywords
    Chemistry, Physical.
    Advisor
    Perry, Joseph W.
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    The study of two-photon absorbing (TPA) chromophores has previously shown that intramolecular charge transfer (ICT) between electron donors (D) and acceptors (A) symmetrically substituted on a π-conjugated bridge can result in large values of the two photon cross section (δ). This work addresses the role of torsion in the π-backbone on δ, modulation of δ by solvent polarity, and development of two-photon excitable molecular sensors. Investigations of the one- and two-photon properties of di(styryl)benzene derivatives with terminal donor groups and cyano acceptors substituted either on the central phenyl ring or on the adjacent vinyl groups show that the position of the cyano group has a significant effect on the geometry and optical properties of the molecules. δ for vinyl substituted molecules is half that for phenylene substituted molecules and is similar to the values obtained for molecules with no acceptor groups. The one- and two-photon spectroscopic differences can be related to the donor-acceptor distance in these molecules and to the degree of torsion in conjugated backbone. Torsional effects on the electronic coupling of multi-chromophore molecules are also investigated. For quadrupolar TPA chromophores, solvent polarity weakly affects the linear absorption but strongly modifies the fluorescence spectral position and quantum yield (η). The TPA peak position does not shift with solvent polarity, however the magnitude of δ increases by up to a factor of two in acetonitrile relative to toluene. Analysis of the data in terms of the stabilization of intramolecular charge transfer by polar solvents is explored. Two-photon absorbing molecular sensors are investigated in which an ion binding group is incorporated as one of the donor groups (D-A-D' ) in a TPA molecule. When one monoaza-15-crown-5-ether macrocycle is bound to the chromophore, the two-photon induced fluorescence signal (ηδ) decreases seven-fold upon addition of magnesium ions, in part as delta is modulated, due to decreased ICT from the nitrogen lone pair involved in ion binding. In molecules incorporating 1,2-bis(o-aminophenoxy)-ethane- N,N,N',N'-tetraacetic acid, a 5-fold enhancement of ηδ is observed upon calcium ion binding in water at 720 nm. Changes in the TPA spectrum upon binding of Ca²⁺ in micellar systems are also observed.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Chemistry
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.