Electronic Supplementary Information High-Performance Organic Field-Effect Transisitor based on Dihexyl-Substitued Dibenzo[d,d ]thieno[3,2-b;4,5-b ]dithiophene Yasuo Miyata*, Eiji Yoshikawa, Takeo Minari, Kazuhito Tsukagoshi*, Shigehiro Yamaguchi Contents 1. Synthesis 2. Single-Crystal X-Ray Analysis of C6-DBTDT 3. X-Ray Diffractions of C6-DBTDT 4. AFM Images of C6-DBTDT 5. Ionization Potential of C6-DBTDT 6. Typical OFET Device Fabrication S1
1. Synthesis General: 1 H NMR (270 MHz) and 13 C NMR (75 MHz) were measured on a JEOL EX270 spectrometer and a BRUKER DPX300 spectrometer, respectively. 13 C NMR (75 MHz) of C6-DBTDT was exceptionally measured on a VARIAN INOVA-300 spectrometer. Chemical shifts are reported in ppm with reference to tetramethylsilane and with the solvent signals as internal standard ( =7.26 ppm for CHCl 3 in 1 H NMR, =77.2 ppm for CDCl 3 in 13 C NMR). High-resolution mass spectra were recorded using a JEOL JMS-T100GC mass spectrometer, and elemental analysis was performed using an ELEMENTAR element analyzer at Sumika Chemical Analysis Service, Ltd. All melting points were measured in aluminum open pans under nitrogen atmosphere by differential scanning calorimeter (DSC) on a SII NanoTechnology DSC6200R at a heating rate of 10 C/min. All reactions were carried out under a nitrogen atmosphere unless otherwise noted. All commercially available materials were reagent grade unless otherwise noted. Synthesis of Compound 1: NBS C 6 H 13 NH 2 AcONH 4 C 6 H 13 NH 2 MeCN 1 49% N-omosuccinimide (53.3 g, 299 mmol) was added in one portion to a stirred solution of 4-hexylaniline (50.5 g, 285 mmol) and ammonium acetate (2.20 g, 28.5 g) in acetonitrile (855 ml) under water bath. The mixture was removed from water bath and stirred for 3h at room temperature (rt). The solvent was evaporated in vacuo, and ethyl acetate was added. The solution was washed with water and brine, and the organic layer was dried with sodium sulfate. The solvent was removed in vacuo. The residue was purified by flash chromatography over silica gel with hexane as an eluent to afford compound 1 (35.6 g, 139 mmol, 48.8% yield) as a deep-red oil. 1 H-NMR (CDCl 3 ): = 7.22 (d, J = 1.9 Hz, 1H), 6.91 (dd, J = 8.1, 1.9 Hz, 1H), 6.68 (d, J = 8.1 Hz, 1H), 3.93 (s, 2H), 2.46 (t, J = 7.7 Hz, 2H), 1.62-1.47 (m, 2H), 1.36-1.24 (m, 6H), 0.88 (t, J = 6.8 Hz, 3H); 13 C NMR (CDCl 3 ): = 141.8, 134.5, 132.2, 128.5, 115.9, 109.5, 34.8, 31.9, 31.7, 29.0, 22.8, 14.3; HRMS (EI+): m/z calcd for C 12 H 18 N: 255.06226; found: 255.06116. Synthesis of Compound 2: C 6 H 13 NH 2 1) NaNO 2 aq 2) KI C 6 H 13 I 1 2 77% S2
Sulfuric acid (95%, 50 g) was added dropwise to a mixture of compound 1 (25.6 g, 100 mmol) and water (450 ml) at rt. The mixture was cooled to 5 C, and a solution of sodium nitrite (8.97 g, 130 mmol) in water (300 ml) was added dropwise to the mixture. After the mixture was stirred for 2h at 10 C, a solution of potassium iodide (133 g, 801 mmol) in water (300 ml) was added to the mixture at 5 C. The mixture was stirred for 2h at rt, and refluxed for 20 min. After cooled to rt, the mixture was poured into a solution of sodium bisulfite (22.5 g, 216 mmol) in water (450 ml). The mixture was extracted with ethyl acetate, and the organic layer was dried over magnesium sulfate. The solvent was removed in vacuo to afford crude compound 2 as a brown oil (28.2 g, 76.7 mmol, 76.7% yield). 1 H-NMR (CDCl 3 ): = 7.72 (d, J = 8.1 Hz, 1H), 7.45 (d, J = 2.0 Hz, 1H), 6.81 (dd, J = 8.1, 2.0 Hz, 1H), 2.52 (t, J = 7.5 Hz, 2H), 1.59-1.54 (m, 2H), 1.36-1.29 (m, 6H), 0.88 (t, J = 6.7 Hz, 3H); 13 C NMR (CDCl 3 ): = 145.1, 140.0, 132.9, 129.6, 129.0, 97.3, 35.3, 31.8, 31.2, 29.0, 22.7, 14.3; HRMS (EI): m/z calcd for C 12 H 16 I: 365.94801; found: 365.94663. Synthesis of Compound 3: C 6 H 13 1) TMS Pd(PPh 3 ) 4 CuI, (i-pr) 2 NH I 2) K 2 CO 3 MeOH, THF C 6 H 13 2 3 71% To a mixture of compound 2 (14.7 g, 40.0 mmol), tetrakis(triphenylphosphine)palladium (0) (0.28 g, 0.40 mmol), cupper(i) iodide (0.15 g, 0.80 mmol), and diisopropylamine (53.6 ml) was added a solution of trimethylsilylacetylene (4.71 g, 48.0 mmol) in diisopropylamine (2.64 ml) dropwise at rt, and the mixture was stirred for 2h. A deposited salt in the reaction mixture was filtered off over silica gel, and the volatiles of the obtained filtrate were removed in vacuo to give an oil. The oil was diluted with tetrahydrofuran (80 ml) and methanol (80 ml). Potassium carbonate (0.55 g, 4.00 mmol) was added to the mixture at rt, and the mixture was stirred for 3h. After the solvent was removed in vacuo, a 1% aqueous solution of ammonium chloride and diethyl ether was added to the residue. The obtained organic layer was dried over magnesium sulfate. The residue was purified by flash chromatography over silica gel with hexane as an eluent to afford compound 3 (7.56 g, 28.5 mmol, 71.2 % yield) as a pale-brown oil. 1 H-NMR (CDCl 3 ): = 7.42 (d, J = 7.8 Hz, 1H), 7.41 (d, J = 1.8 Hz, 1H), 7.07 (dd, J = 7.8, 1.8 Hz,1H), 3.32 (s,1h), 2.57 (t, J = 7.7 Hz, 2H), 1.67-1.51 (m, 2H), 1.37-1.22 (m, 6H), 0.88 (t, J = 6.7 Hz, 3H); 13 C NMR (CDCl 3 ): = 145.8, 133.9, 132.4, 127.3, 125.5, 121.5, 82.2, 81.1, 35.6, 31.7, 31.1, 29.0, 22.7, 14.2; HRMS (EI): m/z calcd for C 14 H 17 : 264.05136; found: 264.05004. Synthesis of Compound 4: S3
C 6 H 13 CuI TMEDA acetone C 6 H 13 C 6 H 13 3 4 45% Compound 3 (7.56 g, 28.5 mmol) was added to a solution of cupper(i) iodide (0.27 g, 1.4 mmol) and N,N,N',N'-tetramethylethylenediamine (0.43 ml, 2.9 mmol) in acetone (29 ml). The mixture was stirred for 5h at rt with bubbling air. The solvent was removed in vacuo, and 1M of hydrochloric acid was added to the residue. The mixture was extracted with chloroform, and the organic layer was dried over magnesium sulfate. The solvent was removed in vacuo, and the residue was recrystallized from toluene to afford compound 4 (11.8 g, 22.0 mmol, 45.0% yield) as a colorless solid. 1 H-NMR (CDCl 3 ): = 7.46 (d, J = 7.8 Hz, 2H), 7.42 (d, J = 1.6 Hz, 2H), 7.08 (dd, J = 7.8, 1.6 Hz, 2H), 2.58 (t, J = 7.6 Hz, 4H), 1.66-1.50 (m, 4H), 1.38-1.23 (m, 12H), 0.88 (t, J = 6.7 Hz, 6H); 13 C NMR (CDCl 3 ): = 146.5, 134.4, 132.7, 127.6, 126.2, 121.4, 81.2, 77.5, 35.8, 31.8, 31.1, 29.0, 22.7, 14.3; HRMS (EI+): m/z calcd for C 28 H 32 2 : 526.08708; found: 526.08501. Synthesis of Compound 5: C 6 H 13 C 6 H 13 4 1) t-buli, THF 2) S 8 3) NaOH aq 4) K 3 [Fe(CN) 6 ] S S C 6 H 13 S S C 6 H 13 5 31% To a solution of compound 4 (10.6 g, 20.0 mmol) in dry tetrahydrofuran (200 ml) was added a solution of t-butyllithium in pentane (1.59 M, 62.9 ml, 100 mmol) dropwise at 78 C, and the mixture was stirred for 1 h at 78 C. Sulfur powder (3.2 g, 100 mmol) was gradually added, and the temperature of the mixture was slowly raised to rt, and the mixture was stirred for 2h. An aqueous solution of sodium hydroxide (1M, 300 ml) and potassium hexacyanoferrate (III) (32.9 g, 100 mmol) were added at rt. After stirred for 1h, the mixture was extracted with chloroform. The obtained organic layer was washed with brine, and then dried over magnesium sulfate. The solvent was removed in vacuo, and the residue was recrystallized from hexane to afford compound 5 (3.07 g, 6.22 mmol, 30.9% yield) as a deep-red solid. 1 H-NMR (CDCl 3 ): = 7.69 (d, J = 8.1 Hz, 2H), 7.63 (d, J = 1.6 Hz, 2H), 7.28 (dd, J = 8.1, 1.6 Hz, 2H), 2.74 (t, J = 7.6 Hz, 4H), 1.72-1.62 (m, 4H), 1.40-1.24 (m, 12H), 0.89 (t, J = 6.8 Hz, 6H); 13 C NMR (CDCl 3 ): = 141.3, 138.8, 135.2, 133.3, 126.7, 123.1, 122.1, 120.2, 36.3, 31.9, 31.8, 29.1, 22.8, 14.3; HRMS (EI+): m/z calcd for C 28 H 32 S 4 : 496.13868; found: 496.13784; melting point: 103 C. S4
Synthesis of C6-DBTDT: S S Ni(COD) 2 PPh 3 S C 6 H 13 S S C 6 H 13 5 toluene C 6 H 13 S S C6-DBTDT 41% C 6 H 13 A mixture of compound 5 (4.79 g, 9.65 mmol), bis(1,5-cyclooctadiene)nickel (0) (2.92 g, 10.6 mmol), and triphenylphosphine (5.57 g, 21.2 mmol) in dry toluene (96.5 ml) was stirred for 1h at rt, and then refluxed for 10h. After cooled at rt, deposited materials were separated from the mixture by filtration over celite. The materials were extracted with hot o-dichlorobenzene, and the volatile of the o-dichlorobenzene solution was removed in vacuo until a solid began to be deposited. The obtained solution was cooled at rt, and C6-DBTDT (1.82 g, 3.92 mmol, 40.6% yield) as a colorless solid was separated from solution by filtration. A pure sample for using OFET devices was obtained by sublimation. 1 H-NMR (CDCl 3 ): = 7.65 (d, J = 7.3 Hz, 2H), 7.57 (d, J = 1.0 Hz, 2H), 7.19 (dd, J = 7.3, 1.0 Hz, 2H), 2.73 (t, J = 7.0 Hz, 4H), 1.73-1.63 (m, 4H), 1.40-1.29 (m, 12H), 0.90 (t, J = 6.8 Hz, 6H); 13 C NMR (CDCl 3 ) : 142.4, 139.6, 136.2, 131.3, 129.8, 125.9, 123.3, 120.4, 36.4, 32.1, 31.9, 29.3, 23.1, 14.5; elemental analysis: calcd (%) for C 28 H 32 S 3 : C 72.36, H 6.94; found: C 72.34, H 6.85; melting point: 236 C. S5
Fig. S1 1 H NMR spectrum of 1 in CDCl 3. Fig. S2 13 C NMR spectrum of 1 in CDCl 3. S6
Fig. S3 1 H NMR spectrum of 2 in CDCl 3. Fig. S4 13 C NMR spectrum of 2 in CDCl 3. S7
Fig. S5 1 H NMR spectrum of 3 in CDCl 3. Fig. S6 13 C NMR spectrum of 3 in CDCl 3. S8
Fig. S7 1 H NMR spectrum of 4 in CDCl 3. Fig. S8 13 C NMR spectrum of 4 in CDCl 3. S9
Fig. S9 1 H NMR spectrum of 5 in CDCl 3. Fig. S10 13 C NMR spectrum of 5 in CDCl 3. S10
Fig. S11 1 H NMR spectrum of C6-DBTDT in CDCl 3. Fig. S12 13 C NMR spectrum of C6-DBTDT in CDCl 3 S11
2. Single-Crystal X-Ray Analysis of C6-DBTDT Intensity data were collected at 100 K on a Rigaku Single Crystal CCD X-ray Diffractometer (Saturn 70 with MicroMax-007) with Mo K radiation ( = 0.71073 Å) and graphite monochromator. The structure was solved by direct methods (SHELXS-97) and refined by the full-matrix least-squares on F 2 (SHELXL-97). All non-hydrogen atoms were refined anisotropically and all hydrogen atoms were placed using AFIX instructions. Single crystals of C6-DBTDT were obtained by slow diffusion of ethanol into a solution of C6-DBTDT in CHCl 3. C 28 H 32 S 3 ; FW = 464.72, crystal size 0.20 x 0.20 x 0.02 mm 3, Orthorhombic, Pbcm, a = 4.12(3) Å, b = 11.09(11) Å, c = 52.8(6) Å, V = 2412(39), Z = 4. The refinement converged to R 1 = 0.1186, wr 2 = 0.3325 (I > 2 (I)), GOF = 1.519. CCDC 830987 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. Fig. S13 (a) ORTEP drawing of C6-BDTDT. Thermal ellipsoids are drawn at the 50% probability level. (b) Side view. Sulfur atoms are shown in red. 3. X-Ray Diffractions of C6-DBTDT X-ray diffractions of vacuum-deposited thin films of C6-DBTDT on the OTS-modified Si/SiO 2 substrates were conducted with a Rigaku RINT-2500V diffractometer with Cu radiation ( = 1.541 Å) in air. Fig. S14 XRD patterns of C6-DBTDT thin films vacuum-deposited at T sub = (a) rt and (b) 80 ºC on the OTS-modified Si/SiO 2 substrates. S12
4. AFM Images of C6-DBTDT AFM images of vacuum-deposited thin films of C6-DBTDT on the OTS-modified Si/SiO 2 substrates were obtained by using SII NanoTechnology SPI4000-SPA300HV in air. Fig. S15 AFM images (10 x 10 m) and height profiles of thin films of C6-DBTDT vacuum-deposited T sub = (a) rt and (b) 80 ºC. 5. Ionization Potential of C6-DBTDT Ionization potential of the vacuum-deposited thin film of C6-DBTDT on the Si substrate was measured by photoelectron yield spectroscopy (PYS) using BUNKOUKEIKI BIP-KV201AE under nitrogen atmosphere. 8.0E-06 6.0E-06 (yield) 1/2 4.0E-06 2.0E-06 0.0E+00 4.00 5.00 6.00 7.00 photon energy (ev) Fig. S16 The photoemission yield spectrum of the vacuum-deposited C6-DBTDT film as a function of photon energy. S13
6. Typical OFET Device Fabrication OFET devices were fabricated with a top-contact configuration. A highly doped p + -Si wafer with 200 nm thick thermally grown SiO 2 (C i = 1.7 x 10 8 F/cm 2 ) was used as a substrate. The substrate was ultrasonically cleaned by acetone and 2-propanol, followed by a sulfuric acid and hydrogen peroxide mixture. After the surface was treated by UV-O 3, the substrate was immersed in octyltrichlorosilane (OTS) solution to form a self-assembled monolayer on the surface. A thin film (ca. 30-40 nm thick) of C6-DBTDT was vacuum-deposited onto the Si/SiO 2 substrate at the substrate temperature of room temperature or 80 C under a pressure of ca. 2x10 4 Pa. The deposition of C6-DBTDT was carried out through a metal mask to define the channel width (Fig. S17). On top of the organic thin film, FeCl 3 (0.3 nm) and gold (40 nm) were sequentially deposited through a shadow mask as source and drain electrodes. The channel length (L) and width (W) were 350 m and 750 m, respectively. Fig. S17 Optical microscope image of the OFET based on a C6-DBTDT thin film. Au FeCl 3 Au FeCl 3 C6-DBTDT SiO 2 p + Si Fig. S18 Schematic cross section of the top-contact OFET with FeCl 3 /Au electrodes. S14
Fig. S19 (a) Transfer and (b) output characteristics of the OFETs based on C6-DBTDT thin films vacuum-deposited at T sub = 80 C with Au (blue) and FeCl 3 /Au (red) electrodes. S15