Visible Absorption Spectroscopy and Structure of Cyanine Dimers in Aqueous Solution: An Experiment for Physical Chemistry

Miin-Liang Horng and Edward L. Quitevis
Department of Chemistry & Biochemistry, Texas Tech University, Lubbock, TX 79409-1061
J. Chem. Educ., 2000, 77 (5), p 637
DOI: 10.1021/ed077p637
Publication Date (Web): May 1, 2000

Abstract

The shape of the visible absorption spectra for cyanine dyes in aqueous solution is concentration dependent. This property is attributed to the formation of dimers and higher aggregates in solution. The shape changes are typically manifested by a splitting of the absorption bands or the appearance of new bands. These spectral features arise from exciton coupling between the molecules in an aggregate. In this experiment, an iterative procedure for obtaining the dimer spectrum from the composite spectra of concentrated dye solutions is used. Simple exciton theory is used to obtain information about the structure of the dimer from its spectrum. The iterative procedure and the application of simple exciton theory are demonstrated using the visible absorption spectra of 1,1'-diethyl-2,2'-cyanine in aqueous solution at different concentrations. In this experiment, concepts in quantum theory and spectroscopy are illustrated. These include energy delocalization, excitons, transition moments, and oscillator strengths. Expanding the scope of analysis to include dye aggregation and exciton theory enhances the pedagogical value of studying the visible absorption spectra of conjugated dyes in the physical chemistry curriculum.

Keywords (Audience):

Upper-Division Undergraduate

Keywords (Domain):

Laboratory Instruction

Keywords (Pedagogy):

Hands-On Learning / Manipulatives

Keywords (Subject):

Dyes / Pigments

Citing Articles

View all 6 citing articles

Citation data is made available by participants in CrossRef's Cited-by Linking service. For a more comprehensive list of citations to this article, users are encouraged to perform a search in SciFinder.

This article has been cited by 6 ACS Journal articles (5 most recent appear below).

  • Cover Image

    Photophysical and Lasing Properties of Rhodamine 6G Confined in Polymeric Nanoparticles

    Virginia Martín, Jorge Bañuelos, Eduardo Enciso, Íñigo López Arbeloa, Ángel Costela, and Inmaculada García-Moreno
    The Journal of Physical Chemistry C2011 115 (10), 3926-3933
    • Photophysical and Lasing Properties of Rhodamine 6G Confined in Polymeric Nanoparticles

      Virginia Martín, Jorge Bañuelos, Eduardo Enciso, Íñigo López Arbeloa, Ángel Costela, and Inmaculada García-Moreno
      The Journal of Physical Chemistry C2011 115 (10), 3926-3933

      The photophysics and laser action of rhodamine 6G (Rh6G) confined in polymeric nanoparticles, based on copolymers of methyl methacrylate and 2-hydroxyethyl methacrylate, are analyzed as a function of the dye concentration, as well as the composition and ...

  • Cover Image

    The Particle Inside a Ring: A Two-Dimensional Quantum Problem Visualized by Scanning Tunneling Microscopy

    Mark D. Ellison
    Journal of Chemical Education2008 85 (9), 1282
    • The Particle Inside a Ring: A Two-Dimensional Quantum Problem Visualized by Scanning Tunneling Microscopy

      Mark D. Ellison
      Journal of Chemical Education2008 85 (9), 1282

      The one-dimensional particle-in-a-box model used to introduce quantum mechanics to students suffers from a tenuous connection to a real physical system. This article presents a two-dimensional model, the particle confined within a ring, that directly ...

  • Cover Image

    Modern Developments in the Physical Chemistry Laboratory

    Samuel A. Abrash
    2007 973 (), 115-151
    • Modern Developments in the Physical Chemistry Laboratory

      Samuel A. Abrash
      2007 973 (), 115-151

      Developments in the physical chemistry laboratory since the publication of the germinal text by Schwenz and Moore (1) are categorized and reviewed. The categories examined include modern instrumentation, current topics in chemistry, integrated ...

  • Cover Image

    Determination of Micellar Microenvironment of Pinacyanol by Visible Spectroscopy

    Raimon Sabaté and Joan Estelrich
    The Journal of Physical Chemistry B2003 107 (17), 4137-4142
    • Determination of Micellar Microenvironment of Pinacyanol by Visible Spectroscopy

      Raimon Sabaté and Joan Estelrich
      The Journal of Physical Chemistry B2003 107 (17), 4137-4142

      The interaction of pinacyanol, a cationic cyanine dye (PIN), with Triton X-100, sodium dodecyl sulfate, and alkyltrimethylammonium bromide micelles was studied by visible spectrophotometry. PIN exists as a monomer and in aggregated form (dimers, trimers, ...

  • Cover Image

    A Spectroscopy Study of the Interaction of Pinacyanol with n-dodecyltrimethylammonium Bromide Micelles

    Raimon Sabaté, Montserrat Gallardo, Alfonso de la Maza, and Joan Estelrich
    Langmuir2001 17 (21), 6433-6437
    • A Spectroscopy Study of the Interaction of Pinacyanol with n-dodecyltrimethylammonium Bromide Micelles

      Raimon Sabaté, Montserrat Gallardo, Alfonso de la Maza, and Joan Estelrich
      Langmuir2001 17 (21), 6433-6437

      The interaction of pinacyanol, a cyanine dye (PIN), with n-dodecyltrimethylammonium bromide (DTAB) at micellar concentration range was studied by visible spectrophotometry. As PIN is present in aggregate and nonaggregate forms, we aimed to determine the ...

Tools

SciFinder Links

SciFinder subscribers:  Click to sign in | Not a SciFinder subscriber? Learn more at www.cas.org

Explore by:


History

  • Received: August 03, 2009

Recommend & Share

  • Share on ACS NetworkACS Network
  • Add to FacebookFacebook
  • Tweet ThisTweet This
  • Add to CiteULikeCiteULike
  • Add to NewsvineNewsvine
  • Digg ThisDigg This
  • Add to DeliciousDelicious

Related Content