Fluorescence and Absorption Spectra and Potential Energy Surfaces of 1,3-Benzodioxole and Coumaran in Their S$_{0}$ and S$_{1}(\pi $,$\pi $*) States

ORAL

Abstract

The fluorescence excitation spectra and dispersed fluorescence spectra of jet-cooled molecules along with ultraviolet and far-infrared absorption spectra of the bicyclic molecules 1,3-benzodioxole and coumaran have been recorded. These spectra have allowed us to determine the two-dimensional potential energy surfaces for the ring-puckering and ring-flapping vibrations for the S$_{0}$ and S$_{1}(\pi $,$\pi $*) electronic states. Both molecules are bent with barriers to planarity in both their ground and excited states. The bent structures for coumaran result from --CH$_{2}$-CH$_{2}$- torsional forces while those for 1,3-benzodioxole are caused by the anomeric effect.

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Authors

  • Katsuhiko Okuyama

  • Kevin Morris

    Stephen F. Austin State University, Texas A\&M University-Commerce, University of Texas at Arlington, Texas A\&M University, University of North Texas, Dept. of Physics, University of Maryland, College Park, Texas A\&M-Commerce, Mississippi State University, Department of Physics and Institute for Quantum Studies, Texas A\&M University, Texas Tech University, Dept. of Materials Science, University of North Texas, Dept. of Chemistry, University of North Texas, Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, WI 54702-4004

  • Kevin Morris

    Stephen F. Austin State University, Texas A\&M University-Commerce, University of Texas at Arlington, Texas A\&M University, University of North Texas, Dept. of Physics, University of Maryland, College Park, Texas A\&M-Commerce, Mississippi State University, Department of Physics and Institute for Quantum Studies, Texas A\&M University, Texas Tech University, Dept. of Materials Science, University of North Texas, Dept. of Chemistry, University of North Texas, Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, WI 54702-4004

  • Kevin Morris

    Stephen F. Austin State University, Texas A\&M University-Commerce, University of Texas at Arlington, Texas A\&M University, University of North Texas, Dept. of Physics, University of Maryland, College Park, Texas A\&M-Commerce, Mississippi State University, Department of Physics and Institute for Quantum Studies, Texas A\&M University, Texas Tech University, Dept. of Materials Science, University of North Texas, Dept. of Chemistry, University of North Texas, Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, WI 54702-4004

  • Jaan Laane

    Department of Chemistry, Texas A\&M University, College Station, TX 77843-3255