Journal of Fluorescence

, Volume 17, Issue 6, pp 749–757 | Cite as

Single Molecule Spectroscopy of Poly 3-octyl-thiophene (P3OT)

  • Rodrigo E. Palacios
  • Paul F. Barbara
Original Paper


We report on the spectroscopy of isolated chains of P3OT, in a highly dilute solution in the inert polymer host poly(methyl–methacrylate) (PMMA). This environment permits a detailed analysis of emission transitions in the 1.9–2.2 eV range by suppressing the formation of the lowest emitting-energy aggregated form of P3OT. Herein it is observed that the 1.9–2.2 eV band is in fact split into low (red) and high (blue) energy forms in a highly analogous situation to that found for the conjugated polymer MEH-PPV. Another focus of this work is an investigation of the interaction of singlet and triplet excitons in P3OT. The results indicate that, like in MEH-PPV, triplet excitons are highly efficient fluorescence quenchers for P3OT, strongly quenching the fluorescence of P3OT under even relatively low excitation intensities.


Single molecule spectroscopy Poly 3-alkyl-thiophene (P3AT) Poly-3-octyl-thiophene (P3OT) Bimodal emission Singlet–triplet interaction 



We gratefully acknowledge the Basic Energy Sciences Program of the Department of Energy and the Robert A. Welch Foundation for support of this research. We thank Brent C. Norris for making the nanoparticle samples that were studied in this paper.


  1. 1.
    Bolognesi A, Giacometti Schieroni A, Botta C, Marinelli M, Mendichi R, Rolandi R, Relini A, Inganas O, Theandher M (2003) High photoluminescence efficiency in substituted polythiophene aggregates. Synth Met 139(2):303–310CrossRefGoogle Scholar
  2. 2.
    Ahn S-H, Czae M-Z, Kim E-R, Lee H, Han S-H, Noh J, Hara M (2001) Synthesis and characterization of soluble polythiophene derivatives containing electron-transporting moiety. Macromolecules 34(8):2522–2527CrossRefGoogle Scholar
  3. 3.
    Bolognesi A, Bajo G, Paloheimo J, Ostergaard T, Stubb H (1997) Polarized electroluminescence from an oriented poly(3-alkylthiophene) Langmuir–Blodgett structure. Adv Mater (Weinheim, Germany) 9(2):121–124CrossRefGoogle Scholar
  4. 4.
    Barta P, Salaneck WR, Zagorska M, Pron A, Niziol S (1996) Electroluminescence of regioregular poly(alkylthiophenes). Adv Mater Opt Electron 6(5, 6):406–408CrossRefGoogle Scholar
  5. 5.
    Uchida M, Ohmori Y, Morishima C, Yoshino K (1993) Visible and blue electroluminescent diodes utilizing poly(3-alkylthiophenes) and poly(alkylfluorenes). Synth Met 57(1):4168–4173CrossRefGoogle Scholar
  6. 6.
    Sirringhaus H, Tessler N, Thomas DS, Brown PJ, Friend RH (1999) High-mobility conjugated polymer field-effect transistors. Adv Solid State Phys 39:101–110Google Scholar
  7. 7.
    Sirringhaus H, Tessler N, Friend RH (1999) Integrated, high-mobility polymer field-effect transistors driving polymer light-emitting diodes. Synth Met 102(1–3):857–860CrossRefGoogle Scholar
  8. 8.
    Li G, Shrotriya V, Huang J, Yao Y, Moriarty T, Emery K, Yang Y (2005) High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends. Nat Mater 4(11):864–868CrossRefGoogle Scholar
  9. 9.
    Yang X, Loos J, Veenstra SC, Verhees WJH, Wienk MM, Kroon JM, Michels MAJ, Janssen RAJ (2005) Nanoscale morphology of high-performance polymer solar cells. Nano Lett 5(4):579–583PubMedCrossRefGoogle Scholar
  10. 10.
    Coakley KM, Liu Y, McGehee MD, Frindell KL, Stucky GD (2003) Infiltrating semiconducting polymers into self-assembled mesoporous titania films for photovoltaic applications. Adv Funct Mater 13(4):301–306CrossRefGoogle Scholar
  11. 11.
    Huynh WU, Dittmer JJ, Alivisatos AP (2002) Hybrid nanorod-polymer solar cells. Science (Washington, DC, United States) 295(5564):2425–2427CrossRefGoogle Scholar
  12. 12.
    Yang C, Orfino FP, Holdcroft S (1996) A phenomenological model for predicting thermochromism of regioregular and nonregioregular poly(3-alkylthiophenes). Macromolecules 29(20):6510–6517CrossRefGoogle Scholar
  13. 13.
    Xu B, Holdcroft S (1993) Molecular control of luminescence from poly(3-hexylthiophenes). Macromolecules 26(17):4457–4460CrossRefGoogle Scholar
  14. 14.
    Sundberg M, Inganaes O, Stafstroem S, Gustafsson G, Sjoegren B (1989) Optical absorption of poly(3-alkylthiophenes) at low temperatures. Solid State Commun 71(6):435–439CrossRefGoogle Scholar
  15. 15.
    Sakurai K, Tachibana H, Shiga N, Terakura C, Matsumoto M, Tokura Y (1997) Experimental determination of excitonic structure in polythiophene. Phys Rev, B Condens Matter 56(15):9552–9556Google Scholar
  16. 16.
    Rumbles G, Samuel IDW, Magnani L, Murray KA, DeMello AJ, Crystall B, Moratti SC, Stone BM, Holmes AB et al (1996) Chromism and luminescence in regioregular poly(3-dodecylthiophene). Synth Met 76(1–3):47–51CrossRefGoogle Scholar
  17. 17.
    Mao H, Xu B, Holdcroft S (1993) Synthesis and structure–property relationships of regioirregular poly(3-hexylthiophenes). Macromolecules 26(5):1163–1169CrossRefGoogle Scholar
  18. 18.
    Luzzati S, Elmino P, Bolognesi A (1996) Luminescence excitation spectroscopy of highly oriented poly(3-octylthiophene)-polyethylene blends. Synth Met 76(1–3):23–26CrossRefGoogle Scholar
  19. 19.
    Kanemoto K, Shishido M, Sudo T, Akai I, Karasawa T, Agari Y (2005) Effect of the dilution in polypropylene on photophysical properties of poly(3-alkylthiophenes). Synth Met 155(1):162–167CrossRefGoogle Scholar
  20. 20.
    Chen TA, Wu XM, Rieke RD (1995) Regiocontrolled synthesis of Poly(3-Alkylthiophenes) mediated by Rieke Zinc—their characterization and solid-state properties. J Am Chem Soc 117(1):233–244CrossRefGoogle Scholar
  21. 21.
    Bolognesi A, Porzio W, Provasoli A, Botta C, Comotti A, Sozzani P, Simonutti R (2001) Structural and thermal behavior of poly(3-octylthiophene): a DSC, C-13 MAS NMR, XRD, photoluminescence, and Raman scattering study. Macromol Chem Phys 202(12):2586–2591CrossRefGoogle Scholar
  22. 22.
    Yamamoto T, Komarudin D, Maruyama T, Arai M, Lee B-L, Suganuma H, Asakawa N, Inoue Y, Kubota K, Sasaki S, Fukuda T, Matsuda H (1998) Extensive studies on p-stacking of poly(3-alkylthiophene-2,5-diyl)s and poly(4-alkylthiazole-2,5-diyl)s by optical spectroscopy, NMR analysis, light scattering analysis, and x-ray crystallography. J Am Chem Soc 120(9):2047–2058CrossRefGoogle Scholar
  23. 23.
    Hu DH, Yu J, Wong K, Bagchi B, Rossky PJ, Barbara PF (2000) Collapse of stiff conjugated polymers with chemical defects into ordered, cylindrical conformations. Nature 405(6790):1030–1033PubMedCrossRefGoogle Scholar
  24. 24.
    Gesquiere AJ, Lee YJ, Yu J, Barbara PF (2005) Single molecule modulation spectroscopy of conjugated polymers. J Phys Chem B 109(25):12366–12371PubMedCrossRefGoogle Scholar
  25. 25.
    Yu J, Lammi R, Gesquiere AJ, Barbara PF (2005) Singlet–triplet and triplet–triplet interactions in conjugated polymer single molecules. J Phys Chem B 109(20):10025–10034PubMedCrossRefGoogle Scholar
  26. 26.
    Barbara PF, Gesquiere AJ, Park SJ, Lee YJ (2005) Single-molecule spectroscopy of conjugated polymers. Acc Chem Res 38(7):602–610PubMedCrossRefGoogle Scholar
  27. 27.
    Kim DY, Grey JK, Barbara PF (2006) A detailed single molecule spectroscopy study of the vibronic states and energy transfer pathways of the conjugated polymer MEH-PPV. Synth Met 156(2–4):336–345CrossRefGoogle Scholar
  28. 28.
    Lee YJ, Kim DY, Grey JK, Barbara PF (2005) Variable temperature single-molecule dynamics of MEH-PPV. Chemphyschem 6(11):2404–2409PubMedCrossRefGoogle Scholar
  29. 29.
    Yu J, Hu DH, Barbara PF (2000) Unmasking electronic energy transfer of conjugated polymers by suppression of O-2 quenching. Science 289(5483):1327–1330PubMedCrossRefGoogle Scholar
  30. 30.
    Szymanski C, Wu C, Hooper J, Salazar MA, Perdomo A, Dukes A, McNeill J (2005) Single molecule nanoparticles of the conjugated polymer MEH-PPV, preparation and characterization by near-field scanning optical microscopy. J Phys Chem B 109(18):8543–8546PubMedCrossRefGoogle Scholar
  31. 31.
    Grey JK, Kim DY, Norris BC, Miller WL, Barbara PF (2006) Size dependent spectroscopic properties of conjugated polymer nanoparticles. J Phys Chem B 110(51):25568–25572PubMedCrossRefGoogle Scholar
  32. 32.
    Palacios RE, Fan F-RF, Bard AJ, Barbara PF (2007) Spectroelectrochemistry studies of the charging and discharging of single conjugated-polymer nanoparticles. Nat Mater (submitted)Google Scholar
  33. 33.
    Hu DH, Yu J, Barbara PF (1999) Single-molecule spectroscopy of the conjugated polymer MEH-PPV. J Am Chem Soc 121(29):6936–6937CrossRefGoogle Scholar
  34. 34.
    Havinga EE, Rotte I, Meijer EW, Tenhoeve W, Wynberg H (1991) Spectra nd electrical-properties of soluble partially alkyl-substituted oligomers of thiophene up to 11 rings. Synth Met 41(1–2):473–478CrossRefGoogle Scholar
  35. 35.
    Tenhoeve W, Wynberg H, Havinga EE, Meijer EW (1991) Substituted 2,2′-5′,2′′-5′′, 2(′X3)-5(′X3), 2(′X4)-5(′X4), 2(′X5)-5(′X5), 2(′X6)-5(′X6), 2(′X7)-5(′X7), 2(′X8)-5(′X8), 2(′X9)-5(′X9), 2(′X10)-undecithiophenes—the longest characterized Oligothiophenes. J Am Chem Soc 113(15):5887–5889CrossRefGoogle Scholar
  36. 36.
    Nakanishi H, Sumi N, Aso Y, Otsubo T (1998) Synthesis and properties of the longest oligothiophenes: the icosamer and heptacosamer. J Org Chem 63(24):8632–8633CrossRefGoogle Scholar
  37. 37.
    Sumi N, Nakanishi H, Ueno S, Takimiya K, Aso Y, Otsubo T (2001) Synthesis and properties of a series of the longest oligothiophenes up to the 48-mer. Bull Chem Soc Jpn 74(5):979–988CrossRefGoogle Scholar
  38. 38.
    Nakanishi H, Sumi N, Ueno S, Takimiya K, Aso Y, Otsubo T, Komaguchi K, Shiotani M, Ohta N (2001) Spectral properties of the longest oligothiophenes in the oxidation states. Synth Met 119(1–3):413–414CrossRefGoogle Scholar
  39. 39.
    Furukawa Y, Akimoto M, Harada I (1987) Vibrational key bands and electrical conductivity of polythiophene. Synth Met 18(1–3):151–156CrossRefGoogle Scholar
  40. 40.
    Monkman AP, Burrows HD, Hartwell LJ, Horsburgh LE, Hamblett I, Navaratnam S (2001) Triplet energies of pi-conjugated polymers. Phys Rev Lett 86(7):1358–1361PubMedCrossRefGoogle Scholar
  41. 41.
    McCullough RD, Lowe RD, Jayaraman M, Anderson DL (1993) Design, synthesis, and control of conducting polymer architectures: structurally homogeneous poly(3-alkylthiophenes). J Org Chem 58(4):904–912CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  1. 1.Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and TechnologyUniversity of TexasAustinUSA
  2. 2.AustinUSA

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