Supplemental Material
Fluorene- and benzofluorene-cored oligomers as low threshold and high gain
amplifying media
Karolis Kazlauskas,1,a) Gediminas Kreiza,1 Olegas Bobrovas,1 Ona Adomėnienė,1 Povilas
Adomėnas,1 Vygintas Jankauskas,2 Saulius Juršėnas1
1
Institute of Applied Research, Vilnius University, Saulėtekio 9-III, LT-10222 Vilnius, Lithuania
2
Department of Solid State Electronics, Vilnius University, Saulėtekio 9-III, LT-10222 Vilnius,
Lithuania
a)
Electronic mail: karolis.kazlauskas@ff.vu.lt
1
Synthesis of fluorene- and benzofluorene-cored oligomers and their intermediates
The starting compounds, i.e., indanone, alkyl and aryl bromides, as well as supplementary materials
(NBS, hydrazine hydrate, ethyleneglycol etc.) were purchased from Sigma Aldrich and used as
received.
2,7-Dibromo-9-(4-hexylphenyl)-9H-fluorene
(1)
and
5,9-Dibromo-7,7-dimethyl-7H-
benzo[c]fluorene (2) were synthesized according to the procedures reported previously.1
2,7-Dibromo-9-butyl-9-(4-hexylphenyl)-9H-fluorene (3) was prepared by an alkylation of (1) at
C9- position. 100 ml flask, connected with reflux condenser and stirred by a magnetic stirrer, was
charged with 40 ml DMSO, 5 g (10.3 mmol) 2,7-dibromo-9-(4-hexylphenyl)-9H-fluorene, 2.12 g
(15.5 mmol) 1-bromobutane, 0.12 g (0.53 mmol) triethylbenzylammonium chloride and 40 g 50%
aqueous sodium hydroxide solution. The mixture was stirred for 28 h at room temperature, then
poured into 250 ml water, extracted with dichloromethane (3 x 50 ml). Organic layer washed by
water 3 times, evaporated. The remainder was crystallized from 2-propanol. White crystals, m.p.
83-840C. Yield 4.8 g (87%).
1
H-NMR (CDCl3), ppm: 7.60-7.63 (d, J=8.1Hz, 2H), 7.49-7.52 (d, J=8.1Hz, 2H), 7.37-7.36 (m,
2H), 7.11-7.05 (m, 4H), 2.61-2.56 (t, J=7.8 Hz, 2H),2.47-2.41 (m, 2H), 1.62-1.59 (m, 2H), 1.341.24 (m, , 8H), 0.94-0.72 (m, 8H).
Br
Br
Br
Br
(3)
(1)
CH3
H13C6
C6H13
Scheme 1 Synthesis route to 2,7-Dibromo-9-butyl-9-(4-hexylphenyl)-9H-fluorene (3)
(9,9-Diethyl-9H-fluoren-2-yl)boronic acid (4) and (9,9-dihexyl-9H-fluoren-2-yl)boronic acid (5)
were prepared via alkylation of fluorene, consequent bromination of the obtained 9,9dialkylfluorene and conversion of the products to the a.m. compounds, according to the previous
reports.2,3
2
2,7-Diaryl-9-butyl-9-(4-hexylphenyl)-9H -benzo(c)fluorenes (6, 7) were prepared by a reaction of
(3) with (9,9-dialkyl-9H-fluoren-2-yl)boronic acids (4) and (5). Intermediate (3) (0.512 g; 1 mmol)
was dissolved in 20 ml toluene. Under argon atmosfere, 2 mmol corresponding boronic acid, 70 mg
(0.1
mmol)
palladium
dichloride
–triphenylphosphine
complex,
55
mg
(0.2
mmol)
triphenylphosphine was added. The mixture was heated up to 700C, 1 g sodium carbonate solution
in 7 ml water was added. The mixture was refluxed under argon atmosphere for 6 h, then cooled
down. 30 ml Toluene was added, the mixture was washed by water, layers separated. The palladium
catalyst was removed from toluene layer by filtration, the solvent evaporated. The remainder was
purified by column chromatography (silica-gel; eluent hexane-dichloromethane, 20:1). Yield 3844%.
OH
Br
+
Br
B
OH
(3)
R
R
(4, 5)
CH3
H13C6
R
R
R
CH3
R
(6, 7)
H13C6
,
here R = C2H5- (6) and n-C6H13- (7).
Scheme 2 Synthesis route to 2,7-Diaryl-9-butyl-9-(4-hexylphenyl)-9H -benzo(c)fluorenes (6, 7)
2,7-Bis(9,9-diethylfluoren-2-yl)-9-butyl-9-(4-hexylphenyl)-9H-fluorene (6)
Colorless solid powder.
1
H NMR (400 MHz CDCl3) 7.77(d, J=8.1 Hz, 2H), 7.75-7.70(m, 6H), 7.62-7.57 (m, 6H), 7.37-
7.26 (m, 8H), 7.11 (d, J=8Hz, 2H), 2.61-2.55 (m, 4H), 2.20-2.10 (m, 8H), 1.57-1.27 (m, 13H), 0.870.81, 0.41-0.37 (m, 22H).
3
C NMR (101 MHz, CDCl3) 153.04, 150.57, 150.16, 142.25, 141.20, 141.03, 140.94, 140.75,
13
140.31, 139.58, 128.46, 127.01, 126.86, 126.67, 126.44, 126.12, 122.93, 122.87, 121.41, 120.12,
119.81, 119.69, 58.87, 56.20, 37.93, 35.50, 32.78, 31.71, 31.29, 29.15, 26.25, 23.17, 22.60, 14.08,
13.91, 8.63, 8.60.
2,7-Bis(9,9-dihexylfluoren-2-yl)-9-butyl-9-(4-hexylphenyl)-9H-fluorene (7)
Colorless to faint yellow solid powder.
1
H NMR (400 MHz CDCl3) 7.89(d, J=8.1 Hz, 2H), 7.77-7.70 (m, 6H), 7.61-7.58 (m, 6H), 7.38-
7.26 (m, 8H), 7.11(d, J=8.1 Hz, 2H), 2.58-2.55 (m, 4H), 2.03-2.02 (m, 8H), 1.57-0.70 (m, 72H).
C NMR (101 MHz, CDCl3) 153.01, 151.40, 151.01, 142.20, 141.06, 140.95, 140.76, 140.34,
13
140.19, 139.56, 128.45, 126.97, 126.75, 126.63, 126.41, 126.02, 122.90, 121.35, 120.11, 119.81,
119.69, 58.89, 55.15, 40.35, 37.97, 35.50, 31.69, 31.46, 31.27, 29.67, 29.14, 26.29, 23.75, 23.15,
22.57, 14.07, 13.99, 13.87.
Similarly, 5,9-Diaryl-7,7-dimethyl-7H-benzo(c)fluorenes (8, 9) were prepared by a reaction of
intermediate (2) with (4) and (5). Intermediate (2) (0.402 g; 1 mmol) was dissolved in 20 ml
toluene. Under argon atmosfere, 2 mmol corresponding fluoren-2-ylboronic acid, 70 mg (0.1 mmol)
palladium dichloride –triphenylphosphine complex, 55 mg (0.2 mmol) triphenylphosphine was
added. The mixture was heated up to 700C, 1 g sodium carbonate solution in 7 ml water was added.
The mixture was refluxed under argon atmosphere for 6 h, then cooled down. 30 ml Toluene was
added, the mixture was washed by water, layers separated. The palladium catalyst was removed
from toluene layer by filtration, the solvent evaporated. The remainder was purified by column
chromatography (silica-gel; eluent hexane-dichloromethane, 20:1). Yield 40-44%.
OH
Br
+
Br
B
OH
H3C
CH3
(2)
R
R
R
(4, 5)
R
R
H3C
CH3
(8, 9)
R
,
here R = C2H5- (8) and n-C6H13- (9).
4
Scheme 3 Synthesis route to 5,9-Diaryl-7,7-dimethyl-7H-benzo(c)fluorenes (8, 9)
5,9-Bis(9,9-diethylfluoren-2-yl)-7,7-dimethyl-7H-benzo(c)fluorene (8)
Colorless solid powder. Glassy state.
1
H NMR (400 MHz CDCl3) 8.89 (d, J=8.1 Hz,1H), 8.48 (d, J=8.1 Hz,1H), 8.09 (d, J=8.1 Hz,1H),
7.90-7.28 (m, 16H), 2.13-2.11 (m, 8H), 1.72 (m, 8H), 0.46 (2 x t, 12H).
C NMR (101 MHz, CDCl3) 155.52, 152.13, 150.67, 150.24, 150.18, 149.99, 141.27, 140.83,
13
140.75, 140.24, 140.09, 139.75, 139.28, 132.55, 130.01, 129.06, 127.53, 127.13, 127.04, 126.94,
126.90, 126.51, 126.33, 126.10, 125.16, 124.97, 124.20, 123.32, 123.00, 122.95, 122.10, 121.50,
121.10, 119.96, 119.76, 119.73, 119.44, 56.26, 56.22, 47.03, 32.86, 32.74, 26.97, 8.70, 8.64.
5,9-Bis(9,9-dihexylfluoren-2-yl)-7,7-dimethyl-7H-benzo(c)fluorene (9)
Colourless solid powder.
1
H NMR (400 MHz CDCl3) 8.91(d, J=8.1 Hz,1H), 8.49 (d, J=8.1 Hz,1H), 8.09 (d, J=8.1 Hz,1H),
7.88-7.28 (m, 19H), 2.07 (m, 8H),1.72 (s, 6H), 1.28-0.81 (m, 48H).
C NMR (101 MHz, CDCl3) 155.51, 152.13, 151.50, 151.06, 151.01, 150.73, 141.03, 140.85,
13
140.82, 140.43, 140.37, 140.15, 139.98, 139.80, 139.29, 132.55, 132.03, 130.03, 128.92, 127.57,
127.12, 127.02, 126.85, 126.80, 126.53, 126.34, 126.05, 125.07, 124.21, 123.32, 122.96, 122.92,
122.08, 121.44, 121.10, 119.97, 119.79, 119.74, 119.54, 55.21, 55.19, 47.02, 40.47, 40.32, 31.52,
29.73, 26.97, 23.89, 23.79, 22.59, 14.05.
Instrumentation for the identification of oligomers
H1, C13 NMR spectra were measured using BRUKER ASCEND 400 (400 MHz) spectrometer.
Purity of the synthesized intermediates was analyzed using Agilent Technologies 6890N Network
GC System and Agilent Technologies 7890C GC systems gas chromatographs. Mass spectra were
set using Agilent Technologies 5975C gas chromatograph/mass selective detector (GC/MSD)
5
system with the triple-axis detector. HRMS mass spectrometry was carried out on a quadrupole,
time-of-flight mass spectrometer (micrOTOF-Q II, Bruker Daltonik GmbH).
Carrier drift mobilities of oligomers
Carrier drift mobilities of the wet-casted neat films of oligomers were measured by xerographic
time-of-light (XTOF) technique in vacuum at room temperature. Unfortunately, the estimation of
the drift mobility for oligomer BF-et was impossible due to the extremely dispersive carrier
transport in the film. The rest oligomers F-et, F-hex and BF-hex exhibited much less dispersive
transport accompanied by the substantial increase of µh with the electric field (Fig. S1.) indicating
importance of energetic disorder in the trap-dominant transport.4 Essentially, the oligomers
exhibited rather high µh ranging from 310-3 cm2/V/s to 810-3 cm2/V/s at an electric field of
1 MV/cm. The carrier drift mobilities (approaching 10-2 cm2/V/s) obtained in wet-casted amorphous
films of the studied oligomers are considered to be very high.5,6
F-et
10-2
F-hex
h (cm2/V/s)
BF-hex
10-3
200
400
600
800
E
1/2
1000
1200
1400
1/2
(V/cm)
Fig. S1. Hole drift mobilities (µh) as a function of the square root of electric field for the neat films
of oligomers F-et, F-hex, BF-hex. Lines are exponential approximations of the experimental data.
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ASE threshold normalized to
the number of absorbed photons (arb. u.)
Amplified spontaneous emission
10
3
10
2
10
1
10
0
10
BF-et
BF-hex
F-et
F-hex
-1
10
0
10
1
10
2
Concentration in PS (wt %)
Fig. S2. ASE threshold (in the units of absorbed power density) as a function of oligomer
concentration in PS matrix.
References
1
K. Kazlauskas, G. Kreiza, E. Radiunas, P. Adomėnas, O. Adomėnienė, K. Karpavičius, J.
Bucevičius, V. Jankauskas, and S. Juršėnas, Phys. Chem. Chem. Phys. 17, 12935 (2015).
2
J.-S. Yang, Y.-R. Lee, J.-L. Yan, and M.-C. Lu, Org. Lett. 8, 5813 (2006).
3
R. Anémian, J.-C. Mulatier, C. Andraud, O. Stéphan, and J.-C. Vial, Chem. Commun. 1608
(2002).
4
H. Bässler, Phys. Stat. Sol. (b) 175, 15 (1993).
5
S. Allard, M. Forster, B. Souharce, H. Thiem, and U. Scherf, Angew. Chem. Int. Ed. 47, 4070
(2008).
6
T. Malinauskas, D. Tomkute-Luksiene, M. Daskeviciene, V. Jankauskas, G. Juska, V. Gaidelis, K.
Arlauskas, and V. Getautis, Chem. Commun. 47, 7770 (2011).
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