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Alternating Binaphthyl−Thiophene Copolymers: Synthesis, Spectroscopy, and Photo...
Pina, J.; Melo, J. Seixas de; Burrows, H. D.; Maçanita, A. L.; Galbrecht, F.; Bünnagel, T.; Scherf, U.The synthesis and a comprehensive spectroscopic and photophysical study are presented of four alternating binaphthyl−oligothiophene copolymers (DP: 10−15 repeat units) in solution at room and low temperature and in the solid state (thin films). Detailed results are presented on absorption, emission, and triplet−triplet absorption spectra together with all relevant quantum yields (fluorescence, intersystem cross...
An effect of side chain length on the solution structure of poly(9,9-dialkylflu...
Knaapila, M.; Almásy, L.; Garamus, V. M.; Ramos, M. L.; Justino, L. L. G.; Galbrecht, F.; Preis, E.; Scherf, U.; Burrows, H. D.; Monkman, A. P.The effect of side chain length of [pi]-conjugated poly(9,9-dialkylfluorene)s has been studied in semi-dilute (10 mg/mL) toluene solutions using small-angle neutron scattering (SANS) and 1H and 2H NMR spectroscopies. Under these conditions, SANS data indicate that poly(9,9-dinonylfluorene) and poly(9,9-dioctylfluorene) are dissolved down to the molecule level and appear as elongated one-dimensional chains (leng...
Excited State Properties of Oligophenyl and Oligothienyl Swivel Cruciforms
Pina, J.; Melo, J. Seixas de; Burrows, H. D.; Galbrecht, F.; Bilge, A.; Kudla, C. J.; Scherf, U.A comprehensive study has been undertaken of the electronic spectral and photophysical properties of two oligophenyl (BPH and BPHF) and one oligothienyl (BTF) swivel cruciforms involving measurements of absorption, fluorescence, and phosphorescence spectra, quantum yields of fluorescence (phiF), phosphorescence (phiPh) and triplet formation (phiT), lifetimes of fluorescence (τF) and of the triplet state (τT), a...
Spectral and Photophysical Studies of Poly[2,6-(1,5-dioctylnaphthalene)]thiophenes
Pina, J.; Melo, J. Seixas de; Burrows, H. D.; Galbrecht, F.; Nehls, B. S.; Farrell, T.; Scherf, U.A complete spectroscopic and photophysical study of three alternating naphthalene-α-thiophene copolymers was undertaken in solution (room and low temperature) and in the solid state (thin films in a Zeonex matrix). The study comprises absorption, emission, and triplet−triplet spectra together with quantitative measurements of quantum yield (fluorescence, intersystem-crossing, internal conversion, and singlet ox...
Influence of Side Chain Length on the Self-Assembly
Knaapila, M.; Dias, F. B.; Garamus, V. M.; Almásy, L.; Torkkeli, M.; Leppänen, K.; Galbrecht, F.; Preis, E.; Burrows, H. D.; Scherf, U.; Monkman, A. P.We report on the phase behavior of poly(9,9-dihexylfluorene) (PF6), poly(9,9-diheptylfluorene) (PF7), poly(9,9-dioctylfluorene) (PF8), poly(9,9-dinonylfluorene) (PF9), and poly(9,9-didecylfluorene) (PF10) in methylcyclohexane (MCH). After a heating−cooling cycle, in the 10−50 mg/mL concentration range, PF6/MCH, PF7/MCH, PF8/MCH, and PF9/MCH systems were found to be gel-like, while PF10/MCH appears less viscous....
Triplet-State and Singlet Oxygen Formation in Fluorene-Based Alternating Copoly...
Fonseca, S. M.; Pina, J.; Arnaut, L. G.; Melo, J. Seixas de; Burrows, H. D.; Chattopadhyay, N.; Alcácer, L.; Charas, A.; Morgado, J.; Monkman, A. P.Data are reported on the triplet states of a series of fluorene-based A-alt-B type alternating copolymers based on pulse radiolysis-energy transfer and flash photolysis experiments. From the pulse radiolysis experiments, spectra are given for eight copolymers involving phenylene, thiophene, benzothiadiazole, and oligothienylenevinylene groups. Quantum yields for triplet-state formation (ΦT) have been obtained b...
Spectral and Photophysical Studies on Cruciform Oligothiophenes in Solution and...
Pina, J.; Melo, J. Seixas de; Burrows, H. D.; Bilge, A.; Farrell, T.; Forster, M.; Scherf, U.The photophysical and spectroscopic properties of a new class of oligothiophene derivatives, designated as cruciform oligomers, have been investigated in solution (room and low temperature) and in the solid state (as thin films in Zeonex matrixes). The study comprises absorption, emission, and triplet−triplet absorption spectra, together with quantitative measurements of quantum yields (fluorescence, intersyste...
Influence of Solvent Quality on the Self-Organization of Archetypical Hairy Rod...
Knaapila, M.; Garamus, V. M.; Dias, F. B.; Almásy, L.; Galbrecht, F.; Charas, A.; Morgado, J.; Burrows, H. D.; Scherf, U.; Monkman, A. P.We report on the nanoscale structure and solvent-induced phase behavior of two, nearly similar π-conjugated hairy-rod polymers, branched side chain poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2/6) and linear side chain poly[9,9-dioctylfluorene-2,7-diyl] (PFO or PF8), in good and bad (or poor) solventsdeuterated toluene and deuterated methylcyclohexane (MCH)at 20 °C. Small-angle neutron scattering (SANS) mea...
Interactions between surfactants and 1,4-phenylene-[9,9-bis(4-phenoxy-butylsulf...
Burrows, H. D.; Lobo, V. M. M.; Pina, J.; Ramos, M. L.; Melo, J. Seixas de; Valente, A. J. M.; Tapia, M. J.; Pradhan, S.; Scherf, U.; Hintschich, S. I.The interaction between the water-soluble anionic conjugated copolymer poly1,4-phenylene-[9,9-bis(4-phenoxy-butylsulfonate)]fluorene-2,7-diyl (PBS-PFP) and various surfactants has been studied in aqueous solution by UV-vis absorption spectra, fluorescence and electrical conductivity. It is suggested from the linear dependence of absorbance, fluorescence and electrical conductivity on concentration that in the a...
Interaction between the Water Soluble Poly1,4-phenylene-[9,9-bis(4-phenoxy buty...
Tapia, M. J.; Burrows, H. D.; Valente, A. J. M.; Pradhan, S.; Scherf, U.; Lobo, V. M. M.; Pina, J.; Melo, J. Seixas deThe interaction has been studied in aqueous solutions between a negatively charged conjugated polyelectrolyte poly1,4-phenylene-[9,9-bis(4-phenoxybutylsulfonate)]fluorene-2,7-diyl copolymer (PBS-PFP) and several cationic tetraalkylammonium surfactants with different structures (alkyl chain length, counterion, or double alkyl chain), with tetramethylammonium cations and with the anionic surfactant sodium dodecyl...
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