Electronic structure and optical properties of electroluminescent spiro-type molecules
1997; American Institute of Physics; Volume: 107; Issue: 7 Linguagem: Inglês
10.1063/1.474615
ISSN1520-9032
AutoresNils Johansson, D. A. dos Santos, Shuxu Guo, Jérôme Cornil, Mats Fahlman, Josef Salbeck, H. Schenk, Hans Arwin, Jean‐Luc Brédas, W. R. Salanek,
Tópico(s)Conducting polymers and applications
ResumoThe electronic structure and optical properties of the propeller-shaped spiro molecules, 2,2′-bis(5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl)-9,9′-spirobifluorene, and 2,2′,7,7′-tetrakis (biphenyl-4-yl)-9,9-spirobifluorene, have been studied by photoelectron spectroscopy, Raman spectroscopy, and spectroscopic ellipsometry. The experimental spectra are analyzed with the help of results from quantum-chemical calculations. The excellent agreement between experiment and theory allows for a detailed characterization of the frontier electronic structure and lowest-energy optical transitions in these novel compounds. It follows that most of the electronic and optical properties of the these spiro-molecules can be deduced by consideration of a single branch; in this case a sexi-phenyl and PBD branch. In particular, although the branches in the spiro molecules are perpendicular to each other, there is considerable interaction at the spiro-center between the π-electron systems of the two branches, indicating, among other things, that chemistry involving either branch is dependent on the other branch.
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