Abstract
A series of fluorene-alt-benzene based conjugated main chain polymers chemically attached with alkyl side chains of different lengths on phenylene rings were designed and synthesized by a palladium catalyzed Suzuki coupling reaction. The UV-vis absorption and fluorescence spectra, thermal stability of spectral property, phase transition behavior and morphology of the synthesized polymers were investigated. With increasing the length of the alkyl side chain, the UV and fluorescence spectra exhibit an obvious blue shift compared with those of the unsubstituted polymer. The alkyl substitution improves the thermal spectral stability of the polymers due to the steric hindrance of the alkyl side chains, thus leading to efficient separation of the main chain backbones. The phase transition behavior is closely related to the length of the alkyl side chains attached on the phenylene rings. The annealed films of the polymers display characteristic nematic liquid crystalline texture. TEM observations indicate that solvent-cast thin deposits of all the polymers show typical fibrillar morphology.
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References
Grell M., Bradley D. D. C., Inbasekaran M., Woo E. P., A glass-forming conjugated main-chain liquid crystal polymer for polarized electroluminescence applications, Adv. Mater. 1997, (9): 798
Scherf U., List E. J. W., Semiconducting polyfluorenes — Towards reliable structure-property relationships, Adv. Mater. 2002, (14): 477
He G. F., Li Y. F., Guo T. F., Yang Y., Thermal annealing induced high performance light-emitting diodes based on poly(9,9′-dioctyl fluorene), Synth. Met., 2003, (137): 1091–1092
Rughooputh S. D. D. V., Nowak M., Hotta S., Heeger A. J., Wudl F., Soluble conducting polymers — The poly(3-alkylthienylenes), Synth. Met., 1987, (21): 41–50
Leclene P., Hennebicq E., Calderone A., Brocorens P., Grimsdale A. C., Müllen K., Brédas J. L., Lazzaroni R., Supramolecular organization in block copolymers containing a conjugated segment: a joint AFM/molecular modeling study, Prog. Polym. Sci., 2003, (28): 55–81
Akcelrud L., Electroluminescent polymers, Prog. Polym. Sci., 2003, (28): 875–962
Geng Y. H., Culligan S. W., Trajkovska A., Wallace J. U., Chen S. H., Monodisperse oligofluorenes forming glassy-nematic films for polarized blue emission, Chem. Mater., 2003, (15): 542–549
Tirapattur S., Belletete M., Drolet N., Bouchard J., Ranger M., Leclerc M., Durocher G., Spectroscopic study of intermolecular interactions in various oligofluorenes: Precursors of light-emitting polymers, J. Phys. Chem. B, 2002, (106): 8959–8966
Nakazawa Y. K., Carter S. A., Nothofer H. G., Scherf U., Lee V. Y., Miller R. D., Scott J. C., Effects of polymer sidebranching in double-and single-layer polyfluorene light-emitting diodes, Appl. Phys. Lett., 2002, (80): 3832–3834
Teetsov J., Fox M. A., Photophysical characterization of dilute solutions and ordered thin films of alkyl-substituted polyfluorenes, J. Mater. Chem., 1999, (9): 2117–2122
Kawana S., Durrell M., Lu J., Macdonald J. E., Grell M., Bradley D. D. C., Jukes P. C., Jones R. A. L., Bennett S. L., X-ray diffraction study of the structure of thin polyfluorene films, Polymer, 2002, (43): 1907–1913
Tang H. Z., Fujiki M., Motonaga M., Alkyl side chain effects of optically active polyfluorenes on their chiroptical absorption and emission properties, Polymer, 2002, (43): 6213–6220
Tanto B., Guha S., Martin C. M., Scherf U., Winokur M. J., Structural and spectroscopic investigations of bulk poly [bis(2-ethyl)hexylfluorene], Macromolecules, 2004, (37): 9438–9448
Chen S. A., Ni J. M., Structure properties of conjugated conductive polymers. 1. Neutral poly(3-alkylthiophene)s, Macromolecules, 1992, (25): 6081–6089
Li Y. N., Vamvounis G., Holdcroft S., Tuning optical properties and enhancing solid-state emission of poly(thiophene)s by molecular control: a postfunctionalization approach, Macromolecules, 2002, (35): 6900–6906
Winokur M. J., Spiegel D., Kim Y., Hotta S., Heeger A. J., Structural and absorption studies of the thermochromic transition in poly(3-hexylthiophene), Synth Met., 1989, (28): C419–C426
Redecker M., Bradley D. D. C., Inbasekaran M., Woo E. P., Mobility enhancement through homogeneous nematic alignment of a liquid-crystalline polyfluorene, Appl. Phys. Lett., 1999, (74): 1400–1402
Grell M., Bradley D. D. C., Inbasekaran M., Ungar G., Whitehead K. S., Woo E. P., Intrachain ordered polyfluorene, Synth. Met., 2000, (111): 579–581
Lieser G., Oda M., Miteva T., Meisel A., Nothofer H. G., Scherf U., Ordering, graphoepitaxial orientation, and conformation of a polyfluorene derivative of the “hairy-rod” type on an oriented substrate of polyimide, Macromolecules, 2000, (33): 4490–4495
Ranger M., Rondeau D., Leclerc M., New well-defined poly(2,7-fluorene) derivatives: Photoluminescence and base doping, Macromolecules, 1997, (30): 7686–7691
Liu B., Yu W. L., Lai Y. H., Huang W., Blue-light-emitting fluorene-based polymers with tunable electronic properties, Chem. Mater., 2001, (13): 1984–1991
Huang H. M., He Q. G., Song Y., Lin H. Z., Yang J. L., Bai F. L., Synthesis and photophysical properties of alternating copolymers containing triphenylamine moieties, Polym. Adv. Technol., 2003, (14): 309–313
Lemmer U., Heun S., Mahrt R. F., Scherf U., Hopmeier M., Siegner U., Göbel E. O., Müllen K., Bässler H., Aggregate fluorescence in conjugated polymers, Chem. Phys. Lett., 1995, (240): 373–378
Zeng G., Yu W. L., Chua S. J., Huang W., Spectral and thermal spectral stability study for fluorene-based conjugated polymers, Macromolecules, 2002, (35): 6907–6914
Chen S. H., Su A. C., Chang C. S., Chen H. L., Ho D. L., Tsao C. S., Peng K. Y., Chen S. A., Aging of poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene)/to luene solutions and subsequent effects on luminescence behavior of cast films, Langmuir, 2004, (20): 8909–8915
Chen S. H., Su A. C., Su C. H., Chen S. A., Crystalline forms and emission behavior of poly(9,9-di-n-octyl-2,7-fluorene), Macromolecules, 2005, (38): 379–385
Ihn K. J., Moulton J., Smith P., Whiskers of poly(3-alkylthiophene)s, J. Polym. Sci. Part B: Polym. Phys., 1993, (31): 735–742
Kline R. J., McGehee M. D., Kadnikova E. N., Liu J. S., Fréchet J. M. J., Toney M. F., Dependence of regioregular poly(3-hexylthiophene) film morphology and field-effect mobility on molecular weight, Macromolecules, 2005, (38): 3312–3319
Surin M., Hennebicq E., Ego C., Marsitzky D., Grimsdale A. C., Müllen K., Brédas J. L., Lazzaroni R., Leclère P., Correlation between the microscopic morphology and the solid-state photoluminescence properties in fluorene-based polymers and copolymers, Chem. Mater., 2004, (16): 994–1001
Chappell J., Lidzey D. G., Jukes P. C., Higgins A. M., Thompson R. L., O’Connor S., Grizzi I., Fletcher R., O’Brien J., Geoghegan M., Jones R. A. L., Correlating structure with fluorescence emission in phase-separated conjugated-polymer blends, Nature Mater., 2003, (2): 616–621
Samori P., Sikharulidze I., Francke V., Müllen K., Rabe J. P., Nanoribbons from conjugated macromolecules on amorphous substrates observed by SFM and TEM, Nanotechnology, 1999, (10): 77–80
Teetsov J. A., Vanden Bout D. A., Imaging molecular and nanoscale order in conjugated polymer thin films with near-field scanning optical microscopy, J. Am. Chem. Soc., 2001, (123): 3605–3606
Teetsov J., Vanden Bout D. A., Near-field scanning optical microscopy studies of nanoscale order in thermally annealed films of poly(9,9-diakylfluorene), Langmuir, 2002, (18): 897–903
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Yang, G., Wang, M. & Liu, T. The photophysical properties and morphology of fluorene-alt-benzene based conjugated polymer. Front. Chem. China 1, 130–137 (2006). https://doi.org/10.1007/s11458-006-0002-4
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DOI: https://doi.org/10.1007/s11458-006-0002-4