SUPPORTING INFORMATION
Solution-Processable BODIPY-Based Small Molecules for Semiconducting Microfibers in Organic Thin-Film Transistors
Mehmet Ozdemir,1,§ Donghee Choi,2,§ Guhyun Kwon, 2 Yunus Zorlu,3 Bunyemin Cosut,3 HyeKyung Kim,2 Antonio Facchetti, 4* Choongik Kim,2* Hakan Usta1* § equal contribution.
1
Department of Materials Science and Nanotechnology Engineering, Abdullah Gül University,
Kayseri, Turkey 2
Department of Chemical and Biomolecular Engineering, Sogang University, Mapo-gu, Seoul,
Korea 3
Department of Chemistry, Gebze Technical University, Gebze, Turkey
4
Polyera Corporation, 8045 Lamon Avenue, Skokie, Illinios 60077, United States
*
Correspondence to: Prof. Hakan Usta (E-mail:
[email protected]), Prof. Choongik Kim (E-mail:
[email protected]), Prof. Antonio Facchetti (E-mail:
[email protected]).
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NH 2NH 2, NaOH
O N H
N H
Ethylene Glycole
H
2 i) n-BuLi, THF
NBS S
Br
DMF
Br
S
ii) Sn(CH 3) 3
(H3 C) 3Sn
S
Sn(CH3 )3
3 NBS
S S
Acedic Acid
Br
S S
Br
i) n-BuLi, THF
(H 3C)3Sn
ii) Sn(CH 3 )3
S S
Sn(CH 3) 3
4
Scheme S1. Synthesis of common intermediates 2, 3, and 4. Synthesis of 2-methylpyrrole (2). Pyrrole-2-carboxaldehyde (6.0 g, 63.1 mmol), NaOH (13.2 g, 0.33 mol) and hyrazine hydrate (12.35 g, 0.39 mol) in ethylene glycole (80 mL) were heated at 200 °C under nitrogen for 3 h. During the course of the reaction, an organic phase was distilled via Dean-Stark trap. The distillate was extracted with diethyl ether, and the organic phase was washed with deionized water, dried over Na2SO4, filtered, and evaporated to dryness to give the pure product as a colorless oil (4.98 g, 97.5% yield). 1H NMR (400 MHz, CDCl3): δ 2.37 (s, 3H), 6.02 (m, 1H), 6.24 (m, 1H), 6.73 (m, 1H), 7.98 (broad s, 1H). Synthesis of 2,5-dibromothiophene. To a stirred solution of thiophene (1.00 g, 11.89 mmol) in anhydrous DMF (10 ml) at room temperature, N-bromosuccinimide (4.34 g, 24.36 mmol) was added, and the resulting mixture was stirred at room temperature for 20 h. Then, the reaction mixture was poured into water, and the product was extracted with CH2Cl2. The organic layer was dried over Na2SO4, filtered, and evaporated to dryness to give a crude product. The crude was purified by column chromatography on silica gel using hexanes as the eluent to give the pure product as a colorless oil (1.88 g, 65% yield). 1H NMR (400 MHz, CDCl3): δ 6.86 (s, 2H).
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Synthesis of 2,5-bis(trimethylstannyl)thiophene (3). To a solution of 2,5-dibromothiophene (1.05 g, 4.13 mmol) in anhydrous THF (30 ml) at -78 °C, n-BuLi (3.47 ml, 8.68 mmol; 2.5 M in hexanes) was added dropwise over 20 min. The reaction mixture was stirred for 1 hour at -78 °C. Then, trimethyltinchloride (1.81 g, 9.1 mmol) was added under nitrogen as a solid, and the resulting mixture was allowed to warm to ambient temperature overnight. The reaction mixture was quenched with water and extracted with diethyl ether. The organic phase was dried over Na2SO4, filtered, and evaporated to dryness to give the pure product as a white solid (1.46 g, 86.5% yield). 1H NMR (400 MHz, CDCl3): δ 0.38 (s, 18H), 7.39 (s, 2H). Synthesis of 5,5'-dibromo-2,2'-bithiophene. To a stirred solution of 2,2’-bithiophene (2.0 g, 12.0 mmol) in acetic acid (30 ml) at room temperature, N-bromosuccinimide (4.49 g, 25.0 mmol) was slowly added, and the reaction mixture was stirred at room temperature for 3 h. Then, the reaction mixture was poured into ice resulting in the formation of a white solid. The white solid was washed with deionized water, dried over Na2SO4, filtered, and evaporated to dryness to give a crude product. The crude was purified by column chromatography on silica gel using hexanes as the eluent, and the pure product was obtained as a pale yellow solid (3.84 g, 98.6% yield). 1H NMR (400 MHz, CDCl3): δ 6.87 (d, 2H, J = 4.0 Hz), 6.98 (d, 2H, J = 4.0 Hz). Synthesis of 5,5’-bis(trimethylstannyl)-2-2’-thiophene (4). To a solution of 5,5’-dibromo 2,2’ bithiophene (1.0 g, 3.08 mmol) in anhydrous THF (40 ml) at -78 °C, n-BuLi (2.6 ml, 6.48 mmol; 2.5 M in hexane) was added dropwise over 20 min, and the reaction mixture was stirred for 2 hour at -78 °C. Then, trimethyltinchloride (1.35 g, 6.8 mmol) was added under nitrogen as a solid, and the resulting reaction mixture was allowed to warm to ambient temperature overnight. The reaction mixture was quenched with water and extracted with hexanes. The organic phase was dried over Na2SO4, filtered, and evaporated to dryness to give a crude product. The crude
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was recrystallized with ethanol to give the pure product as an off-white crystalline solid (1.19 g, 39.2% yield). 1H NMR (400 MHz, CDCl3): δ 0.39 (s, 18H), 7.10 (d, 2H, J = 3.2 Hz), 7.29 (d, 2H, J = 3.2 Hz).
Figure S1. The X-ray crystal structures of compounds 11 (A), 22 (B), and 33 (C) reported in the literature, and the perspective views of their inter-ring dihedral angles between borondipyrromethene and meso-aromatic unit planes.
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Figure S2. Optimized molecular geometries of BDY-1 (A), 2,2′:5′,2′′-terthiophene (B) and 2,2′:5′,2′′:5′′,2′′′-quaterthiophene (C) showing computed HOMO and LUMO energy levels and topographical representations (DFT, B3LYP/6-31G**).
Figure S3. Positive ion and linear mode MALDI TOF-MS spectrum of BDY-3T-BDY.
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Figure S4. Positive ion and linear mode MALDI TOF-MS spectrum of BDY-4T-BDY.
Figure S5. Thermogravimetric analysis (TGA) of the compounds BDY-3T-BDY and BDY-4TBDY at temperature ramps of 10 °C min-1 under N2.
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Figure S6. Optical absorption spectra of BDY-1 and meso-alkyl substituted BODIPY compound BDY-C11 in THF.
Figure S7. Fluorescence emission spectra of BDY-3T-BDY (A) and BDY-4T-BDY (B) in THF and Toluene solutions (1x10-5 M) (Excitation wavelength= 510 nm).
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Figure S8. (a) Transfer and (b) output characteristics of thin-film transistors based on vapordeposited BDY-3T-BDY thin films.
Figure S9. (a) Transfer and (b) output characteristics of thin-film transistors based on vapordeposited BDY-4T-BDY thin films.
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Figure S10. (a) Transfer and (b) output characteristics of thin-film transistors based on solutionsheared BDY-3T-BDY thin films.
Figure S11. θ-2θ X-ray diffraction (XRD) scan of solution-sheared BDY-3T-BDY thin film.
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Figure S12. θ-2θ X-ray diffraction (XRD) scan of vacuum-deposited BDY-3T-BDY thin film.
Figure S13. θ-2θ X-ray diffraction (XRD) scan of vacuum-deposited BDY-4T-BDY thin film.
Figure S14. Optical microscopy images of solution-sheared BDY-4T-BDY thin film showing the source-drain electrodes, and the directions of solution-shearing and charge-transport.
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Figure S15. Transfer (A) and output (B) characteristics of thin-film transistors based on solution-sheared BDY-4T-BDY thin films with source-drain electodes deposited parallel to the major fiber alignment direction.
Figure S16. AFM topographic image (left) and top-view SEM images (right) of solution-sheared BDY-3T-BDY thin film. Scale bar denotes 4 µm in AFM and 50 µm in SEM image. Arrow shows the direction of solution shearing.
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Figure S17. AFM image of vacuum-deposited BDY-3T-BDY thin film. Scale bar denotes 1 µm.
Figure S18. AFM image of vacuum-deposited BDY-4T-BDY thin film. Scale bar denotes 1 µm.
Table S1. Crystal data and refinement parameters for BODIPY. Empirical Formula Formula weight (g. mol-1) Temperature (K) Wavelength (Å) Crystal system Space group a (Å) b (Å) c (Å) α(°) β(°) γ(°) Crystal size (mm) V (Å3)
C15H12BBrF2N2S 381.05 299(2) 0.71073 Monoclinic P 21/c 6.3938(11) 15.112(2) 15.986(3) 90 96.680(10) 90 0.142 x 0.207 x 0.425 1534.1(4) S12
Z ρcalcd (g. cm−3) µ (mm−1) F(000) θ range for data collection (°) h/k/l Reflections collected Independent reflections Absorption correction Data/restraints/parameters Goodness-of-fit on F2 Final R indices [I > 2σ(I)] R indices (all data) Largest diff. peak and hole (e.Å−3)
4 1.650 2.832 760 1.86 – 26.37 -7/7, -18/18, -19/18 16075 3120 [R(int) = 0.0983] Multi-scan 3120 / 0 / 201 1.040 R1= 0.0462, wR2= 0.1052 R1= 0.0783, wR2= 0.1199 0.521 and -0.517
Table S2. Organic thin-film transistors characteristics based on vacuum-deposited thin films of BDY-3T-BDY and BDY-4T-BDY at different deposition temperature (TD). Devices were measured under vacuum. Compound
BDY-3T-BDY
BDY-4T-BDY
TD (°C)
µ (cm2/Vs)
20
1.7×10-4
37
9.0×107
50
7.3×10-5
53
6.1×105
80
-
-
-
20
5.3×10-4
75
3.5×105
50
2.6×10-5
51
2.4×106
80
-
-
-
VT (V)
Ion/Ioff
REFERENCES
1. Benniston, A. C.; Copley, G.; Harriman, A.; Rewinska, D. B.; Harrington, R. W.; Clegg, W. A “Donor−Acceptor Molecular Dyad Showing Multiple Electronic Energy-Transfer Processes in Crystalline and Amorphous States” J. Am. Chem. Soc. 2008, 130, 7174–7175. 2. Bura, T.; Leclerc, N.; Fall, S.; Lévêque, P.; Heiser, T.; Retailleau, P.; Rihn, S.; Mirloup, A.; Ziessel, R. “High-Performance Solution-Processed Solar Cells and Ambipolar Behavior in Organic Field-Effect Transistors with Thienyl-BODIPY Scaffoldings” J. Am. Chem. Soc. 2012, 134, 17404–17407. S13
3. C. Yang, Y.; Guo, Q.; Chen, H.; Zhou, Z.; Guo, Z.; Shen, Z. “Thienopyrrole-expanded BODIPY as a potential NIR photosensitizer for photodynamic therapy” Chem. Commun. 2013, 49, 3940-3942.
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