Femtosecond Two-Photon Absorption Spectroscopy of Poly(fluorene) Derivatives Containing Benzoselenadiazole and Benzothiadiazole
AbstractWe have investigated the molecular structure and two-photon absorption (2PA) properties relationship of two push–pull poly(fluorene) derivatives containing benzoselenadiazole and benzothiadiazole units. For that, we have used the femtosecond wavelength-tunable Z-scan technique with a low repetition rate (1 kHz) and an energy per pulse on the order of nJ. Our results show that both 2PA spectra present a strong 2PA (around 600 GM (1 GM = 1 × 10−50 cm4·s·photon−1)) band at around 720 nm (transition energy 3.45 eV) ascribed to the strongly 2PA-allowed 1Ag-like → mAg-like transition, characteristic of poly(fluorene) derivatives. Another 2PA band related to the intramolecular charge transfer was also observed at around 900 nm (transition energy 2.75 eV). In both 2PA bands, we found higher 2PA cross-section values for the poly(fluorene) containing benzothiadiazole unit. This outcome was explained through the higher charge redistribution at the excited state caused by the benzothiadiazole group as compared to the benzoselenadiazole and confirmed by means of solvatochromic Stokes shift measurements. To shed more light on these results, we employed the sum-over-states approach within the two-energy level model to estimate the maximum permanent dipole moment change related to the intramolecular charge transfer transition. View Full-Text
Scifeed alert for new publicationsNever miss any articles matching your research from any publisher
- Get alerts for new papers matching your research
- Find out the new papers from selected authors
- Updated daily for 49'000+ journals and 6000+ publishers
- Define your Scifeed now
Gonçalves Vivas, M.; Dario Fonseca, R.; de Paula Siqueira, J.; Renato Mendonça, C.; Rodrigues, P.C.; De Boni, L. Femtosecond Two-Photon Absorption Spectroscopy of Poly(fluorene) Derivatives Containing Benzoselenadiazole and Benzothiadiazole. Materials 2017, 10, 512.
Gonçalves Vivas M, Dario Fonseca R, de Paula Siqueira J, Renato Mendonça C, Rodrigues PC, De Boni L. Femtosecond Two-Photon Absorption Spectroscopy of Poly(fluorene) Derivatives Containing Benzoselenadiazole and Benzothiadiazole. Materials. 2017; 10(5):512.Chicago/Turabian Style
Gonçalves Vivas, Marcelo; Dario Fonseca, Ruben; de Paula Siqueira, Jonathas; Renato Mendonça, Cleber; Rodrigues, Paula C.; De Boni, Leonardo. 2017. "Femtosecond Two-Photon Absorption Spectroscopy of Poly(fluorene) Derivatives Containing Benzoselenadiazole and Benzothiadiazole." Materials 10, no. 5: 512.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.