JOURNAL OF POLYMER SCIENCE PART A: POLYMER CHEMISTRY DOI 10.1002/POLA
Holmes, A. B.; Burroughes, J. H.; Marks, R. N.; Taliani, C.; Brad-
HOMO and LUMO distribution maps for the sulfone oligomer
11e0 (the structures were simplified by replacing the hexyl
and octyl chains with methyl groups to reduce the calcula-
tion time) and its sulfide analog were calculated at the
B3LYP/6-31G* level and are shown in Figure 9. For the sul-
fide trimer, substantial localization of the HOMO on the sul-
fur atom of the phenothiazine unit is observed, whereas the
LUMO is delocalized over the whole trimer. In contrast, for
sulfone trimer 11e0 the HOMO is delocalized over more of
the trimer, while the LUMO is less delocalized than is the
case with the sulfide.
ley, D. D. C.; Dos Santos, D. A.; Bre´das, J. L.; Logdlund, M.;
¨
Salaneck, W. R. Nature 1999, 397, 121–128; (c) Greenham, N.
C.; Moratti, S. C.; Bradley, D. D. C.; Friend, R. H.; Holmes, A. B.
Nature 1993, 365, 628–630; (d) Mullen, K.; Scherf, U. Organic
¨
Light Emitting Devices: Synthesis, Properties and Applications;
Wiley-VCH: Weinheim, 2006.
2 (a) Kamtekar, K. T.; Monkman, A. P.; Bryce, M. R. Adv Mater
2010, 22, 572–582; (b) Beaupre, S.; Bourdreault, P.-L. T.; Leclerc,
M. Adv Mater 2010, 22, E6–E27.
3 (a) Leclerc, M. J Polym Sci Part A: Polym Chem 2001, 39,
2867–2873; (b) Scherf, U.; List, E. J. W. Adv Mater 2002, 14,
477–487; (c) Polyfluorenes, Adv Polym Sci 212; Scherf, U.,
Neher, D., Eds; Springer-Verlag: Berlin, 2008.
CONCLUSIONS
A series of new fluorene trimers and polymers incorporating
N-arylphenothiazine-S,S-dioxide units have been prepared in
good yields following a facile multi-step route involving pal-
ladium-catalyzed cross-coupling methodology. The materials
are deep blue emitters which show no solvatochromism or
ICT state. Comparing the solution and film emission spectra
of polymer 14d with the sulfide analog 15, a distinct batho-
chromic shift was observed for 15, which can be attributed
to the increase of conjugation through the phenothiazine sys-
tem (15) due to the presence of lone pairs of electrons on
sulfur, compared to the sulfone unit (14d). PLQYs are 15-
30% in solution and between 14–25% in film for trimers
11a–f. Polymers 14a–d demonstrated very high PLQYs in so-
lution (UPL 74–84%) and good PLQYs in film (UPL 28–47%).
Triplet energies were ET 2.48 eV for trimers and 2.23 eV and
2.19 eV for co-polymers 14a–d and 15, respectively. For the
trimers, the pendant N-aryl group influences the HOMO lev-
els, which range from ꢀ5.75 to ꢀ5.24 eV (based on solution
electrochemical data). The LUMO levels were observed
accordingly at ꢀ2.51 to ꢀ2.03 eV. This influence of the pend-
ant group is absent in the co-polymers with 15% incorpora-
tion of phenothiazine-S,S-dioxide units. The optical band
gaps were 3.2 eV for the oligomers and 3.0 eV for the
phenothiazine-S,S-dioxide polymers 14a–d. Hence, (F-SN)n
co-polymers possess a higher HOMO than polyfluorene
homo-polymers. The HOMO and LUMO distribution maps for
trimer 11e0 and its sulfide (phenothiazine) derivative were
calculated at the B3LYP/6-31G* level and show that the
HOMO for the sulfide trimer is more localized on the sulfur
atom of the phenothiazine unit, whereas the HOMO of trimer
11e is more delocalized over the whole p-system. These
results establish that N-arylphenothiazine-S,S-dioxide and
N-arylphenothiazine units are versatile units for incorpora-
tion into fluorene-based polymers which may be applicable
in PLED applications.
4 (a) Cho, S. Y.; Grimsdale, A. C.; Jones, D. J.; Watkins, S. E.;
Holmes, A. B. J Am Chem Soc 2007, 129, 11910–11911; (b)
Gong, X.; Iyer, P. K.; Moses, D.; Bazan, G. C.; Heeger, A. J.;
Xiao, S. S. Adv Funct Mater 2003, 13, 525–530; (c) Kappaun, S.;
Scheiber, H.; Trattnig, R.; Zojer, E.; List, E. J. W.; Slugovc, C.
Chem Commun 2008, 5170–5172; (d) List, E. J. W.; Guentner,
R.; de Freitas, P. S.; Scherf, U. Adv Mater 2002, 14, 374–378.
5 (a) Kamtekar, K. T.; Vaughan, H. L.; Lyons, B. P.; Monkman,
A. P.; Pandya, S. U.; Bryce, M. R. Macromolecules 2010, 43,
4481–4488; (b) King, S. M.; Perepichka, I. I.; Perepichka, I. F.;
Dias, F. B.; Bryce, M. R.; Monkman, A. P. Adv Funct Mater
2009, 19, 586–591; (c) Perepichka, I. I.; Perepichka, I. F.; Bryce,
M. R.; Palsson, L.-O. Chem Commun 2005, 3397–3399.
6 (a) Grisorio, R.; Piliego, C.; Cosma, P.; Fini, P.; Mastrorilli, P.;
Gigli, G.; Suranna, G. P.; Nobile, C. F. J Polym Sci Part A:
Polym Chem 2009, 47, 2093–2104; 6 (b) Li, Y.; Wu, H.; Zou, J.;
Ying, L.; Yang, W.; Cao, Y. Org Electron 2009, 10, 901–909; 6 (c)
Liu, J.; Zou, J.; Yang, W.; Wu, H.; Li, C.; Zhang, B.; Peng, J.;
Cao, Y. Chem Mater 2008, 20, 4499–4506.
7 Li, J. Y.; Ziegler, A.; Wegner, G. Chem Eur J 2005, 11,
4450–4457.
8 (a) Hsieh, B.-Y.; Chen, Y. J Polym Sci Part A: Polym Chem
2009, 47, 833–844; (b) Padhy, H.; Huang, J.-H.; Sahu, D.; Patra,
D.; Kekuda, D.; Chu, C.-W.; Lin, H.-C. J Polym Sci Part A: Polym
Chem 2010, 48, 4823–4834.
9 Yang, L. Y.; Wang, C.; Li, L. Q.; Janietz, S.; Wedel, A.; Hua, Y.
L.; Yin, S. G. J Polym Sci Part A: Polym Chem 2007, 45,
4291–4299.
10 Gessner, T.; Schmidt, H.-W.; Thelakkat, M.; Baete, M. Patent
Applications 2005-EP12647, 2006056465, 25.11.2005, 2006.
11 (a) Lee, J.; Lee, J.-I.; Park, M.-J.; Jung, Y. K.; Cho, N. S.;
Cho, H. J.; Hwang, D.-H.; Lee, S.-K.; Park, J.-H.; Hong, J.; Chu,
H. Y.; Shim, H.-K. J Polym Sci Part A: Polym Chem 2007, 45,
1236–1246; (b) Park, M.-J.; Lee, J.; Jung, I. H.; Park, J.-H.;
Hwang, D.-H.; Shim, H.-K. Macromolecules 2008, 41,
9643–9649.
This work was funded by the TSB as part of the TOPLESS pro-
ject and by EPSRC. We thank Dr. G. Williams (Zumtobel LED
Division) for supporting this work.
12 Pasini, M.; Giovanella, U.; Betti, P.; Bolognesi, A.; Botta, C.;
Destri, S.; Porzio, W.; Vercelli, B.; Zotti, G. ChemPhysChem
2009, 10, 2143–2149.
REFERENCES AND NOTES
1 (a) Burroughes, J. H.; Bradley, D. D. C.; Brown, A. R.; Marks,
R. N.; Mackey, K.; Friend, R. H.; Burn, P. L.; Holmes, A. B. Na-
ture 1990, 347, 539–541; (b) Friend, R. H.; Gymer, R. W.;
13 (a) Lakowitz, J. R., Principles of Fluorescence Spectroscopy;
Kluwer Academic/Plenum Publishers: New York, 1999; (b) Mar-
delli, M.; Olmsted, J. J Photochem 1977, 7, 277–285.
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