Supporting Information
The N=S=N Link as Electron Accepting Moiety for Stable, SolutionProcessable Conjugated Oligomers
Mingfeng Wang, Yanming Sun, Minghong Tong, Eneida S. Chesnut, Jung Hua Seo, Rajeev
Kumar, Fred Wudl*
Department of Chemistry and Biochemistry, Center for Polymers and Organic Solids, Mitsubishi
Chemical Center for Advanced Materials and Materials Research Laboratory, University of
California, Santa Barbara, CA 93106-6105
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Synthesis of 9,9-didodecylfluorene-2,7-bisphthalimide
To dimethylacetamide (dried on molecular sieves over 3 days, 200 mL) in a Schlenk roundbottom flask (300 mL) was added 9,9-didodecyl-2,7-dibromofluorene (12.0 g, 18.0 mmol),
followed by addition of potassium phthalimide (6.64 g, 36.0 mmol) and copper (I) iodide (dried
in oven, 6.84 g, 36.0 mmol). The mixture was stirred under argon for 10-20 min at room
temperature and subsequently stirred at 180 oC. After 32 h the reaction mixture was cooled to
room temperature and was poured into 4 N HCl (1200 mL). To this solution was added CH2Cl2
(700 mL) and the mixture was stirred vigorously for 30 min. Then the organic layer was isolated,
followed by washing with distilled water (400 mL/portion, three times) and brine (400
mL/portion, three times). Finally the organic layer was separated and dried over anhydrous
Na2SO4. After filtration and solvent evaporation, the product was purified by column
chromatography (silica gel, DCM/n-hexane = 3:1). A yellowish/brownish sticky glass was
obtained. Yield: 7.45 g (52%). 1H-NMR (CD2Cl2, 500 MHz):  (ppm) = 7.98 (dd, 4H), 7.86 (d,
2H), 7.81 (dd, 4H), 7.45-7.50 (m, 4H), 2.00-1.95 (m, 4H), 1.30-1.00 (m, 36H), 0.85-0.70 (m,
10H).
Synthesis of 9,9-didodecylfluorene-2,7-diamine
The fluorene derivative 7 (6.35g, 8.02 mmol) and anhydrous ethanol (150 mL) were mixed
in a Schlenk round-bottom flask (250 mL). The mixture was purged with argon under stirring for
ca. 10 min, followed by addition of hydrazine monohydrate (5.2 mL, 80.2 mmol). The mixture
was refluxed (90-95 oC) for 18 h under argon atmosphere. After this period 5.2 mL (80.2 mmol)
more of hydrazine monohydrate was added to the reaction mixture. And the mixture was
refluxed for another 4 h. After cooling to room temperature, the mixture was filtered, the solvent
was removed under vacuum and the residue was dissolved in diethyl ether (ca. 200 mL) and
again filtered. The organic phase was washed with distilled water (200 mL/portion, three times)
and brine (200 mL/portion, three times) and dried over anhydrous Na2SO4. Filtration and solvent
evaporation resulted in a brown viscous oil. Yield: 3.90 g (91%). 1H-NMR (CD2Cl2, 500 MHz):
 (ppm) = 7.33-7.30 (dd, 2H), 6.65-6.60 (dd, 4H), 4.1-3.8 (s, 4H), 1.90-1.80 (m, 4H), 1.30-1.02
(m, 36H), 0.90-0.85 (t, 6H), 0.70-0.55 (broad signal, 4H).
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Synthesis of 2-bromo-9,9-didodecylfluorene
The synthesis of this compound followed a modified procedure from literature.1 KOH (11.2
g, 200 mmol) was added to 10 mL of DMSO in a 50 mL Schlenk flask. The mixture was bubbled
with N2 for ca. 5 min. Then 2-bromofluorene (4.5 g, 18 mmol) was added to this mixture in one
portion. The mixture turned from colorless to orange immediately. Then 1-bromododecane (11.0
mL, 44 mmol) was added to the mixture quickly with a syringe, resulting in a dark yellow
mixture. The mixture was bubbled with N2 for 30 min, then heated to 60 oC under N2 atmosphere
for 2 days. After cooling down to room temperature, the mixture was poured into distilled water
(200 mL), and then was extracted with n-hexane twice (150 mL/portion). The organic layer was
washed with distilled water (twice, 200 mL/portion) and then with brine (twice, 200 mL/portion)
and dried over anhydrous Na2SO4. Then the mixture was filtered, followed by removal of solvent
under vacuum. The crude product was purified by column chromatography (hexane/silica gel).
Yield: 8.133 g (78%). 1H-NMR (500 MHz, CD2Cl2):  (ppm) = 7.68-7.70 (t, 1H), 7.58-7.59 (d,
1H), 7.50 (s, 1H), 7.45-7.47 (d, 1H), 7.33-7.34 (m, 3H), 1.93-1.98 (m, 4H), 1.05-1.28 (m, 36H),
0.86-0.91 (t, 6H), 0.59 (m, 4H).
Synthesis of 9,9-Didodecylfluorene-2-phthalimide
To dimethyl- acetamide (dried on molsieves, 40 mL) was added 9,9- didodecyl-2bromofluorene (4.0 g, 6.88 mmol). After addition of potassium phthalimide (1.27 g, 6.88 mmol)
and copper(I) iodide (dried in oven, 1.31 g, 6.88 mmol) the mixture was stirred under argon for
five minutes at room temperature and subsequently stirred at 180 °C. After 18 h the reaction
mixture was cooled to room temperature and was poured into 4 N HCl (100 mL). To this
solution was added CH2Cl2 (100 mL), and the organic layer was isolated and subsequently
washed with water and brine and dried over Na2SO4. After filtration and evaporation of the
solvent the product was purified by column chromatography (silica gel, CH2Cl2/n-hexane 3:1). A
yellowish/brownish sticky glass was obtained with a yield of 2.1 g (47.7%). 1H-NMR (CDCl3,
500 MHz):  (ppm) = 7.96-8.02 (m, 2H), 7.78-7.83 (m, 3H), 7.72-7.74 (d, 1H), 7.42-7.47 (m,
2H), 7.32-7.39 (m, 3H), 1.95-2.02 (t, 4H), 1.05-1.45 (m, 36H), 0.85-0.90 (m, 6H), 0.60-0.70 (m,
4H).
Synthesis of 9,9-didodecylfluorene-2-amine
9,9-didodecylfluorene-2-phthalimide (1.14g, 1.76 mmol) and hydrazine monohydrate (0.8
mL, 16.5 mmol) were stirred under argon in refluxing ethanol (20mL) for 18h. After this period,
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0.8mL of hydrazine was added and reaction was stopped 4 hours later. A white solid by-product
was formed. After cooling to room temperature, the mixture was filtered, and the solvent was
removed in vacuum. The residue was dissolved in diethyl ether, filtered and then washed with
distilled water and brine (three times each). Product was dried overnight over Na2SO4. After
filtration and evaporation of the solvent, a brown oil was obtained. Yield: 0.654g (71.2%). 1HNMR (CD2Cl2, 500 MHz):  (ppm) = 7.55-7.45 (d, 2H), 7.28-7.21 (m, 2H), 7.2-7.1 (t, 1H), 3.83.7 (s, 2H), 2.0-1.8 (m, 4H), 1.4-1.0 (m, 36H), 0.9-0.8 (t, 6H), 0.7-0.5 (broad signal, 4H).
Synthesis of N-sulfinyl-9,9-didodecylfluorene-1-amine
9,9-Didodecylfluorene-2-amine (0.254 g, 0.486 mmol) was dissolved in anhydrous benzene
(7 mL) in a Schlenk round-bottom flask. To this mixture was added N-sulfinyl-ptoluenesulfonamide (0.158 g, 0.730 mmol) quickly under N2 atmosphere. The mixture turned
from light brown to orange immediately after addition of N-sulfinyl-p-toluenesulfonamide. The
mixture was stirred at room temperature for 22 h, followed by filtration and drying under
vacuum. The residue was redissolved in anhydrous pentane and filtered again. The procedure
was repeated twice to completely remove the pentane-insoluble p-toluenesulfonamide. A dark
yellow solid was obtained after drying the filtrate under vacuum. Yield: 0.180g (65.2%). 1HNMR (CDCl3, 500 MHz):  (ppm) = 7.98-7.92 (d, 1H), 7.89-7.87 (s, 1H), 7.78-7.74 (d, 2H), 7.47.3 (s, 3H), 2.02-1.95 (m, 4H), 1.45-1.00 (m, 36H), 0.90-0.85 (m, 6H), 0.68-0.58 (broad signal,
4H). IR: max 2927, 2852, 1604, 1456, 1286, 1261, 1149, 1026, 891, 833, 737, 633 cm-1. EI+-MS:
563.4 (calculated); m/z 563.4 (measured).
Dimerization of 9,9-didodecylfluorene-2-amine
N-sulfinyl-9,9-didodecylfluorene-1-amine (100 mg, 0.18 mmol) was dissolved in dry
toluene (6 mL) in a Schlenk round-bottom flask (50 mL) and to it was added excess sodium
metal (4.5 mg, 0.20 mmol) quickly under N2 atmosphere. The mixture was bubbled with argon
for ca. 10 min and then heated at 120-130 oC under N2 atmosphere, resulting in a deeper color
with increasing heating time. The mixture turned from dark yellow to deep red after 30 min of
refluxing. After 2.5 h, the mixture was cooled down to r.t. under N2 atmosphere, followed by
dilution with 10 mL of dry toluene and then bubbled with dry air for 30 min. The solvent was
removed under vacuum at room temperature. The residue was redissolved in anhydrous pentane
(10 mL). The mixture was filtered through a PTFE filter (pore size: 0.2 m). The filtrate was
dried under vacuum at room temperature, giving a red oily material. The crude product was
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dissolved in CH2Cl2 (0.5 mL), to which CH3CN (freshly dried, 10 mL) was added. The
precipitates were collected by centrifugation (2400 g/min, 5 min). This precipitation procedure
was repeated twice resulting in a red tar-like compound at room temperature. Yield: 134 mg
(70%). 1H-NMR (CD2Cl2, 600 MHz):  (ppm) = 7.70-7.67 (t, 2H), 7.60-7.50 (m, 2H), 7.377.7.26 (m, 3H), 2.01-1.87(t, 4H), 1.2-0.9 (m, 39H), 0.8-0.7 (t, 8H), 0.6-0.5(broad signal, 5H).
C-NMR (CD2Cl2, 600 MHz):  (ppm) = 151.08, 150.48, 144.74, 139.73, 139.39, 126.46,
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126.11, 122.21, 119.10, 118.95, 54.46, 39.49, 31.15, 29.23, 28.86, 28.82, 28.80, 28.78, 28.61,
28.56, 28.54, 23.08, 21.91, 13.10. IR: max 2920, 2852, 1446, 1259, 1092, 1012, 974, 877, 798,
739, 677, 631 cm-1. FD+-MS: 1062.9 (calculated); m/z 1062.7 (measured).
References:
1) Liu, S.-J.; Zhao, Q.; Chen, R.-F.; Deng, Y.; Fan, Q.-L.; Li, F.-Y.; Wang, L.-H.; Huang, C.-H.;
Huang, W. Chem. Eur. J. 2006, 12, 4351.
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Figure S1. 13C-NMR (CD2Cl2) spectrum of compound 5.
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Figure S2. Cyclic voltammograms of compound 5 in CH2Cl2 (electrolyte: 0.1 M
N+(C4H9)4PF6-; scanning rate: 1000 mV/s) on a Pt electrode.
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Figure S3. 1H-NMR (CD2Cl2) spectrum of compound 7.
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Figure S4. 1H-NMR (CD2Cl2) spectrum of compound 8.
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Figure S5. 13C-NMR (CDCl3) spectrum of compound 9.
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Figure S6. EI-mass spectrum of compound 9.
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Figure S7. 1H-NMR (CDCl3) spectrum of compound 10a from the reaction of compound 9 with
DMAP.
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Figure S8. FTIR spectrum of compound 10a from the reaction of compound 9 with DMAP. For
comparison, the FTIR spectra of compound 8 and 9 are also presented here.
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Figure S9. UV-vis absorption spectrum of compound 10a (in THF) from the reaction of
compound 9 with DMAP. For comparison, the FTIR spectra of compound 8 and 9 are
also presented here.
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Figure S10. FAB-mass spectrum of compound 10b.
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Figure S11. 1H-NMR (CDCl3) spectrum of compound 10c from the reaction of compound 9 with sodium
metal.
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Figure S12. 1H-NMR (CDCl3) spectrum of compound 10c from the reaction of compound 9 with metal
sodium.
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Figure S13. UV-vis absorption spectrum of compound 10b THF in comparison to that
of compound 10c.
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Figure S14. UV-vis absorption and PL spectra of compound 10c in toluene (Figure A) and in the
solid state (Figure B).
Figure S15. PL spectra of compound 5, compound 10b and 10c in toluene.
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Figure S16. Cyclic voltammograms of compound 10c solution (solvent: CH2Cl2;
electrolyte: 0.1 M N+(C4H9)4PF6-; scanning rate: 100 mV/s) on a Pt electrode.
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Figure S17. UPS spectrum of compound 10c films on Au substrates.
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Figure S18. UV-vis absorption (Figure A) and PL (Figure B) spectra of the composites of MEHPPV/10c in diluted solution of toluene.
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Figure S19. UV-vis absorption (Figure A) and PL (Figure B) spectra of P3HT/10c in diluted solution
of toluene.
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Figure S20. UV-vis absorption (Figure A) and PL (Figure B) spectra of P3HT/5 in films on glass
substrates.
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