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Supplementary Information

Architecting layered molecular packing in substituted benzobisbenzothiophene (BBBT) semiconductor crystals

Toshiki Higashino,*a Shunto Arai,b Satoru Inoue,b Seiji Tsuzuki,c Yukihiro Shimoi,c

Sachio Horiuchi,a Tatsuo Hasegawa,*b Reiko Azumia

E-mail: t-higashino@aist.go.jp

t-hasegawa@ap.t.u-tokyo.ac.jp

a Electronics and Photonics Research Institute, National Institute of Advanced Industrial

Science and Technology (AIST), Tsukuba, 305-8565, Japan. b Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan. c Research Center for Computational Design of Advanced Functional Materials

(CD-FMat), National Institute of Advanced Industrial Science and Technology (AIST),

Tsukuba, 305-8568, Japan.

Electronic Supplementary Material (ESI) for CrystEngComm.This journal is © The Royal Society of Chemistry 2020

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Synthesis

Commercially available materials were used as received. Anhydrous solvents

(dimethyl sulfoxide: DMSO and pyridine) were purchased from Wako Pure Chemical

Industries. All reactions were conducted under argon atmosphere. For thin-layer

chromatography (TLC) analysis, Merck pre-coated glass plates (TLC Silica gel 60

F254) were used. Silica gel used in chromatographic separations was obtained from

Wako Pure Chemical Industries (Wakogel® C-200). 1H NMR (400 MHz) and 13C NMR

(100 MHz) spectra were measured with a Bruker AVANCE 400 spectrometer with

CDCl3 as a solvent using Me4Si or residual solvent as an internal standard.

Scheme S1 Synthesis of diC10-BBBT and Ph-BBBT-C10.

2-(4-Decylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4a)

A mixture of 1-bromo-4-decylbenzene (7.43 g, 25.0 mmol, 1.0 eq.), Pd(dppf)Cl2 (1.02 g,

1.25 mmol, 5 mol%), potassium acetate (9.81 g, 100 mmol, 4.0 eq.), and

bis(pinacolato)diboron (9.52 g, 37.5 mmol, 1.5 eq.) in anhydrous DMSO (70 mL) was

stirred for 24 h at 80 °C. After cooling down to room temperature, the reaction mixture

was poured into a NH4Cl solution, and then filtered through Celite. The residue was

washed with EtOAc, and the filtrate was extracted with EtOAc. The combined organic

layer was washed with water and brine, dried over Na2SO4, filtered, and concentrated

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under reduced pressure. The residue was subjected to silica gel column chromatography

(hexane, Rf = 0.3), to afford 4a (7.60 g, 22.1 mmol, yield 88%) as a colourless oil.

GC/MS (EI) m/z = 344; 1H NMR (400 MHz, CDCl3) δ 7.72 (d, J = 8.0 Hz, 2H), 7.19 (d,

J = 8.0 Hz, 2H), 2.61 (t, J = 8.0 Hz, 2H), 1.64-1.56 (m, 2H), 1.34 (s, 12H), 1.33-1.22 (m,

14H), 0.88 (t, J = 7.2 Hz, 3H).

2-([1,1'-Biphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4b)

A mixture of 4-bromo-1,1'-biphenyl (5.83 g, 25.0 mmol, 1.0 eq.), Pd(dppf)Cl2 (1.02 g,

1.25 mmol, 5 mol%), potassium acetate (9.81 g, 100 mmol, 4.0 eq.), and

bis(pinacolato)diboron (9.52 g, 37.5 mmol, 1.5 eq.) in anhydrous DMSO (70 mL) was

stirred for 24 h at 80 °C. After cooling down to room temperature, the reaction mixture

was poured into a NH4Cl solution, and then filtered through Celite. The residue was

washed with EtOAc, and the filtrate was extracted with EtOAc. The combined organic

layer was washed with water and brine, dried over Na2SO4, filtered, and concentrated

under reduced pressure. The residue was subjected to silica gel column chromatography

(CH2Cl2:hexane = 1:2, Rf = 0.5) and recrystallized from hexane, to afford 4b (6.33 g,

22.6 mmol, yield 90%) as a white solid. GC/MS (EI) m/z = 344; 1H NMR (400 MHz,

CDCl3) δ 7.72 (d, J = 8.0 Hz, 2H), 7.19 (d, J = 8.0 Hz, 2H), 2.61 (t, J = 8.0 Hz, 2H),

1.64-1.56 (m, 2H), 1.34 (s, 12H), 1.33-1.22 (m, 14H), 0.88 (t, J = 7.2 Hz, 3H).

4,4''-Didecyl-2',5'-bis(methylsulfinyl)-1,1':4',1''-terphenyl (5a)

A mixture of 1,4-dibromo-2,5-bis(methylsulfinyl)benzene (3)S1 (0.360 g, 1.00 mmol,

1.0 eq.), 4a (1.03 g, 3.00 mmol, 3.0 eq.), Pd(dppf)Cl2 (0.082 g, 0.10 mmol, 10 mol%),

potassium carbonate (0.829 g, 6.00 mmol, 6.0 eq.), and benzyltriethylammonium

chloride (0.228 g, 1.00 mmol, 1.0 eq.) in toluene/water (32/8 mL) was stirred for 24 h at

90 °C. After cooling down to room temperature, to the reaction mixture was slowly

added a 2N-HCl solution, and then filtered through Celite. The residue was washed with

CHCl3, and the filtrate was extracted with CHCl3. The combined organic layer was

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washed with water and brine, dried over Na2SO4, filtered, and concentrated under

reduced pressure. The residue was subjected to silica gel column chromatography

(CHCl3, Rf = 0.2). The resulting solid was washed with MeOH, to afford 5a (0.56 g,

0.88 mmol, yield 88%) as a white solid. GC/MS (EI) m/z = 635; 1H NMR (400 MHz,

CDCl3) δ 8.06 (s, 2H), 7.38 (d, J = 8.4 Hz, 4H), 7.28 (d, J = 8.4 Hz, 4H), 2.67 (t, J = 7.6

Hz, 4H), 2.40 (s, 6H), 1.70-1.62 (m, 4H), 1.38-1.25 (m, 28H), 0.89 (t, J = 6.8 Hz, 6H).

4-Decyl-2',5'-bis(methylsulfinyl)-1,1':4',1'':4'',1'''-quaterphenyl (5b)

A mixture of 1,4-dibromo-2,5-bis(methylsulfinyl)benzene (3)S1 (0.360 g, 1.00 mmol,

1.0 eq.), 4a (0.517 g, 1.50 mmol, 1.5 eq.), 4b (0.420 g, 1.50 mmol, 1.5 eq.), Pd(dppf)Cl2

(0.082 g, 0.10 mmol, 10 mol%), potassium carbonate (0.829 g, 6.00 mmol, 6.0 eq.), and

benzyltriethylammonium chloride (0.228 g, 1.00 mmol, 1.0 eq.) in toluene/water (32/8

mL) was stirred for 24 h at 90 °C. After cooling down to room temperature, to the

reaction mixture was slowly added a 2N-HCl solution, and then filtered through Celite.

The residue was washed with CHCl3, and the filtrate was extracted with CHCl3. The

combined organic layer was washed with water and brine, dried over Na2SO4, filtered,

and concentrated under reduced pressure. The residue was subjected to silica gel

column chromatography (CHCl3, Rf = 0.2). The resulting solid was washed with MeOH,

to afford 5b (0.17 g, 0.30 mmol, yield 30%) as a white solid. GC/MS (EI) m/z = 570; 1H

NMR (400 MHz, CDCl3) δ 8.12 (s, 1H), 8.10 (s, 1H), 7.73 (d, J = 8.4 Hz, 2H),

7,69-7.65 (m, 2H), 7.56 (d, J = 8.4 Hz, 2H), 7.52-7.47 (m, 2H), 7.43-7.38 (m, 2H), 7.30

(d, J = 8.4 Hz, 2H), 2.68 (t, J = 7.6 Hz, 2H), 2.45 (s, 3H), 2.41 (s, 3H), 1.71-1.63 (m,

2H), 1.38-1.25 (m, 14H), 0.89 (t, J = 6.8 Hz, 3H).

2,8-Didecyl-benzo[1,2-b:4,5-b']bis[b]benzothiophene (diC10-BBBT)

A mixture of 5a (0.254 g, 0.400 mmol, 1.0 eq.), phosphorus pentoxide (34 mg, 0.24

mmol, 0.6 eq.) and trifluoromethanesulfonic acid (8 mL) was stirred for 72 h at room

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temperature. The reaction mixture was poured into ice-water (100 mL). The yellow

precipitate was collected by suction filtration and dried under vacuum. The residue was

assumed to be the sulfonium salt. Demethylation of the solid was achieved by refluxing

in anhydrous pyridine (20 mL) for 12 h. After cooling down to room temperature, the

reaction mixture was diluted by water. The resulting precipitate was collected by

suction filtration and was purified by being passed through silica gel column (CHCl3

eluent) and recrystallization from toluene/EtOH, to afford diC10-BBBT (68 mg, 0.12

mmol, yield 30%) as a white solid. M.p. 208 °C; GC/MS (EI) m/z = 570; 1H NMR (400

MHz, CDCl3) δ 8.52 (s, 2H), 8.10 (d, J = 8.0 Hz, 2H), 7.66 (s, 2H), 7.30 (dd, J = 8.0,

1.6 Hz, 2H), 2.77 (t, J = 7.6 Hz, 4H), 1.76-1.66 (m, 4H), 1.42-1.24 (m, 28H), 0.88 (t, J =

6.8 Hz, 6H).

2-Decyl-8-phenyl-benzo[1,2-b:4,5-b']bis[b]benzothiophene (Ph-BBBT-C10)

A mixture of 5b (0.154 g, 0.270 mmol, 1.0 eq.), phosphorus pentoxide (38 mg, 0.27

mmol, 1.0 eq.) and trifluoromethanesulfonic acid (8 mL) was stirred for 72 h at room

temperature. The reaction mixture was poured into ice-water (100 mL). The yellow

precipitate was collected by suction filtration and dried under vacuum. The residue was

assumed to be the sulfonium salt. Demethylation of the solid was achieved by refluxing

in anhydrous pyridine (20 mL) for 12 h. After cooling down to room temperature, the

reaction mixture was diluted by water. The resulting precipitate was collected by

suction filtration and was purified by being passed through silica gel column (CHCl3

eluent) and recrystallization from toluene, to afford Ph-BBBT-C10 (44 mg, 0.087

mmol, yield 32%) as a white solid. M.p. 347 °C; GC/MS (EI) m/z = 506; 1H NMR (400

MHz, CDCl3) δ 8.59 (s, 1H), 8.56 (s, 1H), 8.26 (d, J = 8.0 Hz, 1H), 8.12 (d, J = 8.0 Hz,

1H), 8.08 (s, 1H), 7.75-7.67 (m, 4H), 7.53-7.47 (m, 2H), 7.40 (tt, J = 7.6, 1.6 Hz, 1H),

7.32 (dd, J = 8.0, 1.6 Hz, 1H), 2.78 (t, J = 7.6 Hz, 2H), 1.76-1.67 (m, 2H), 1.42-1.24 (m,

14H), 0.88 (t, J = 6.8 Hz, 3H).

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Solvent solubilities and thermal properties

Fig. S1 TG-DTA and DSC curves of diC10-BBBT and Ph-BBBT-C10.

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Fig. S2 Room-temperature solubilities and phase transition temperatures of

diC10-BBBT, Ph-BBBT-C10, and their BTBT analogs.S2-S5

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Crystal structures

Table S1 Crystallographic data.

Crystals diC10-BBBT Ph-BBBT-C10

Empirical formula C38H50S2 C34H34S2

Formula weight 570.93 506.76

Crystal shape colorless plate colorless plate

Crystal size (mm3) 0.18 × 0.14 × 0.086 0.24 × 0.24 × 0.010

Crystal system monoclinic monoclinic

Space group C2/c P21/c

a (Å) 70.5573(12) 57.3030(16)

b (Å) 4.29828(11) 7.80425(19)

c (Å) 10.8138(3) 6.13566(16)

α (°) 90 90

β (°) 91.4263(18) 92.479(2)

γ (°) 90 90

V (Å3) 3278.54(14) 2741.34(12)

Z 4 4

Total refls. 17114 36899

Uniq. refls. (Rint) 3723 (0.0216) 5149 (0.0556)

Uniq. refls. (I > 2σ(I)) 3212 3703

Refined params. 281 377

Dcalc (g/cm3) 1.157 1.228

R1, wR2 (I > 2σ(I)) 0.0329, 0.0907 0.0654, 0.1540

R1, wR2 (all data) 0.0397, 0.0950 0.0859, 0.1675

GOF 1.033 1.038

Temperature (K) 296 296

CCDC number 1964819 1964820

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Hirshfeld Surface Analysis

Fig. S3 The Hirshfeld surfaces for BBBT (phase A and phase B),S6,S7 diC4-BBBT,S6

diC10-BBBT, and Ph-BBBT-C10. Red areas and letters indicate intermolecular short

contacts.

Fig. S4 The fingerprint plots for BBBT (phase A and phase B), S6,S7 diC4-BBBT, S6

diC10-BBBT, and Ph-BBBT-C10

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Intermolecular Interaction Energy

Fig. S5 Molecular arrangements and intermolecular interaction energies between the

central black-colored molecule and another in BBBT (phase A).S6

Fig. S6 Molecular arrangements and intermolecular interaction energies between the

central black-colored molecule and another in BBBT (phase B).S7

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Fig. S7 Molecular arrangements and intermolecular interaction energies between the

central black-colored molecule and another in diC4-BBBT.S6

Fig. S8 Molecular arrangements and intermolecular interaction energies between the

central black-colored molecule and another in diC10-BBBT.

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Fig. S9 Molecular arrangements and intermolecular interaction energies between the

central black-colored molecule and another in Ph-BBBT-C10.

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Thin-film properties

Fig. S10 (a)(d) Optical images, (b)(e) crossed-Nicols polarized micrographs and (c)(f)

AFM height profiles of the blade-coated thin films: (a)(b)(c) diC10-BBBT and (d)(e)(f)

Ph-BBBT-C10.

Fig. S11 (a) Optical image and (b) crossed-Nicols polarized micrographs of

large-area, single-domain, and single-bilayer Ph-BBBT-C10 ultrathin film obtained by

blade-coating method. The patterned yellow rods are evaporated gold.

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TFT properties

Fig. S12 (a)(b) Crossed-Nicols polarized micrographs of the solution-crystallized TFT

devices and (c)(d) plots of mobility as a function of VG in the saturation region: (a)(c)

diC10-BBBT and (b)(d) Ph-BBBT-C10.

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