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Structural and elec...
Structural and electronic properties of poly(9,9-dialkylfluorene)-based alternating copolymers in solution : An NMR spectroscopy and density functional theory study
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Justino, L. L. G. (författare)
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Luísa Ramos, M. (författare)
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Abreu, P. E. (författare)
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Charas, A. (författare)
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Morgado, J. (författare)
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Scherf, U. (författare)
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Minaev, B. F. (författare)
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- Ågren, Hans (författare)
- KTH,Teoretisk kemi och biologi
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Burrows, H. D. (författare)
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(creator_code:org_t)
- 2013-08-21
- 2013
- Engelska.
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 117:35, s. 17969-17982
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- The structural and electronic properties of three alternating poly(9,9-dialkylfluorene) copolymers, poly[2,7-(9,9-bis(octyl)-fluorene)-alt- benzothiadiazole] (F8BT), poly[2,7-(9,9-bis(2′-ethylhexyl)-fluorene)-alt- thiophene S,S-dioxide] (PFTSO2), and poly[2,7-(9,9-bis(2′-ethylhexyl)- fluorene)-alt-1,4-phenylene] (PFP), containing, respectively, benzothiadiazole (BT), thiophene S,S-dioxide, and phenylene groups, have been investigated and compared to those of the homopolymer poly[2,7-(9,9-bis(2′-ethylhexyl)- fluorene)] (PF2/6). The NMR spectra and corresponding shielding tensors of the 1H and 13C nuclei have been studied in solution and are interpreted by density functional theory (DFT) with complete geometry optimization using the B3LYP functional. Particular emphasis is placed on the conformational behavior and electronic properties in the electronic ground state. In addition, time-dependent DFT is applied to obtain detailed insight into the character of selected excited states. A new TDDFT interpretation is presented for optical absorption spectra of singlet and triplet states that have previously been reported for these fluorene-based conjugated copolymers using photoexcitation and pulse radiolysis-energy transfer studies. As well as providing detailed assignment of excited states, the results show that the triplet excitation is slightly more localized than S1 excitation, in agreement with experimental observations. The DFT analysis provides a link between structure and NMR, optical, electronic properties, allowing optimization of the potential of such polymers for photovoltaic and electroluminescence applications.
Ämnesord
- NATURVETENSKAP -- Kemi -- Fysikalisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Physical Chemistry (hsv//eng)
Nyckelord
- Alternating copolymer
- Conformational behavior
- Conjugated copolymers
- Density functional theory studies
- Electronic ground state
- Geometry optimization
- Singlet and triplet state
- Structural and electronic properties
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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