| Title: | Optical Absorption and Emission Properties of End-capped Oligothienoacenes: A Joint Theoretical and Experimental Study |
| Author: |
Aspuru-Guzik, Alan; Delgado, Carmen Ruiz; Ferrón, Cristina Capel; Osuna, Reyes Malavé; Hernández, Víctor; Navarrete, Juan T. López; Sanchez-Carrera, Roel
Note: Order does not necessarily reflect citation order of authors. |
| Citation: | Sánchez-Carrera, Roel S., M. Carmen Ruiz Delgado, Cristina Capel Ferrón, Reyes Malavé Osuna, Victor Hernández, Juan T. López Navarrete, and Alán Aspuru-Guzik. 2010. Optical absorption and emission properties of end-capped oligothienoacenes: a joint theoretical and experimental study. Organic Electronics 11(10): 1701-1712. |
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Optical_Absorption_and_Emission_Properties.pdf (1.398Mb; PDF)
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| Abstract: | The electron–vibration coupling in a family of silyl end-capped oligothienoacenes is investigated on the basis of a joint experimental and theoretical study using UV–vis absorption and emission spectroscopies and density functional theory calculations. Well-resolved vibronic progressions are found in the low-temperature absorption and emission profiles of these silyl-functionalized organic molecules. As the size of the oligomer lengthens a bathochromic shift is observed in the near-UV–vis range, indicative of the extension of the effective π-conjugation. The absorption and emission bands are practically mirror-symmetric. The combination of two normal modes with frequencies of \( \sim 1500 cm^{−1}\) and \(\sim 500 cm^{−1}\) determines the main vibronic progression in absorption and emission for all the series, although for larger oligomers (n = 6, 7, and 8) the presence of low-frequency normal modes (\(\sim100 cm^{−1}\)) is also evident. The spacing of the vibrational features is slightly larger in absorption than in emission; this agrees with the predicted shifting of the C−C stretching modes of the inner-most ring toward the high-frequency region as a result of the reversal of the single–double C−C pattern in the electronic excited-state. Our calculations indicate that the contributions of the end-capping groups to the total relaxation energy of the \(S_0 \rightarrow S_1\) and \(S_1 \rightarrow S_0\) transitions are almost negligible. This result suggest that the vibronic structure and to a large extent the spectral profiles of the silyl end-capped oligothienoacenes are mainly determined by their respective oligothienyl core. |
| Published Version: | http://dx.doi.org/10.1016/j.orgel.2010.07.001 |
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| Citable link to this page: | http://nrs.harvard.edu/urn-3:HUL.InstRepos:9637920 |
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