PREPARATION OF POLYMERS COMPRISING AT LEAST ONE BENZO[C][1,2,5]THIADIAZOL-5,6-DICARBONITRILE-UNIT

Abstract

A polymer containing at least one unit of formula

##STR00001##

is prepared by treating a compound of formula

##STR00002##

wherein Y.sup.2 is I, Br, Cl or O—S(O).sub.2CF.sub.3,
with an S-donor agent, in order to obtain the compound of formula

##STR00003##

wherein Y.sup.2 is as defined for the compound of formula (5).

Claims

1. A process for the preparation of a polymer comprising at least one unit of formula ##STR00043## wherein Ar.sup.1 and Ar.sup.2 are independently from each other and at each occurrence C.sub.6-14-arylene or a 5 to 15 membered heteroarylene, wherein Ar.sup.1 and Ar.sup.2 can be substituted with one to four substituents selected from the group consisting of C.sub.1-30-alkyl, CN and C.sub.6-14-aryl, and wherein at least two adjacent Ar.sup.1, respectively, at least two adjacent Ar.sup.2 can be connected via an -(L).sub.m- linker, wherein L is at each occurrence selected from the group consisting of CR.sup.1R.sup.2, C═CR.sup.1R.sup.2, C═O and SiR.sup.1R.sup.2, wherein R.sup.1 and R.sup.2 are individually from each other and at each occurrence H or C.sub.1-20-alkyl, and m is 1 or 2, o is an integer from 1 to 8, and n is an integer from 1 to 8, said process comprising (i) treating a compound of formula ##STR00044## wherein Y.sup.2 is I, Br, Cl or O—S(O).sub.2CF.sub.3, with an S-donor agent, in order to obtain the compound of formula ##STR00045## wherein Y.sup.2 is as defined for the compound of formula (5).

2. The process of claim 1, wherein in the polymer comprising at least one unit of formula (1) Ar.sup.1 and Ar.sup.2 are independently from each other and at each occurrence C.sub.6-10-arylene or a 5 to 9 membered heteroarylene, wherein Ar.sup.1 and Ar.sup.2 can be substituted with one to four substituents selected from the group consisting of C.sub.1-30-alkyl, CN and C.sub.6-14-aryl, and wherein at least two adjacent Ar.sup.1, respectively, at least two adjacent Ar.sup.2 can be connected via an -(L).sub.m- linker, wherein L is at each occurrence selected from the group consisting of CR.sup.1R.sup.2, C═CR.sup.1R.sup.2, C═O and SiR.sup.1R.sup.2, wherein R.sup.1 and R.sup.2 are individually from each other and at each occurrence H or C.sub.1-20-alkyl, and m is 1 or 2.

3. The process of claim 2, wherein in the polymer comprising at least one unit of formula (1) Ar.sup.1 and Ar.sup.2 are independently from each other and at each occurrence a 5 to 9 membered heteroarylene, wherein Ar.sup.1 and Ar.sup.2 can be substituted with one to four substituents selected from the group consisting of C.sub.1-30-alkyl, CN and C.sub.6-14-aryl, and wherein at least two adjacent Ar.sup.1, respectively, at least two adjacent Ar.sup.2 can be connected via an -(L).sub.m- linker, wherein L is at each occurrence selected from the group consisting of CR.sup.1R.sup.2, C═CR.sup.1R.sup.2, C═O and SiR.sup.1R.sup.2, wherein R.sup.1 and R.sup.2 are individually from each other and at each occurrence H or C.sub.1-20-alkyl, and m is 1 or 2.

4. The process of claim 3, wherein in the polymer comprising at least one unit of formula (1) Ar.sup.1 and Ar.sup.2 are independently from each other and at each occurrence a 5 membered heteroarylene, wherein Ar.sup.1 and Ar.sup.2 can be substituted with one to four substituents selected from the group consisting of C.sub.1-30-alkyl, CN and C.sub.6-14-aryl.

5. The process of claim 4, wherein in the polymer comprising at least one unit of formula (1) o is an integer from 1 to 6, and n is an integer from 1 to 6.

6. The process of claim 5, wherein in the polymer comprising at least one unit of formula (1) o is an integer from 1 to 4, and n is an integer from 1 to 4.

7. The process of claim 1, which process comprises the additional steps of further comprising (ii) treating the compound of formula (4) as obtained in step (i) with a compound of formula ##STR00046## wherein Ar.sup.1 and o are as defined for the polymer comprising at least one unit of formula (1), and Z.sup.b is selected from the group consisting of B(OZ.sup.1)(OZ.sup.2), SnZ.sup.1Z.sup.2Z.sup.3, ##STR00047## wherein Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6 are independently from each other and at each occurrence H or C.sub.1-6-alkyl, in the presence of catalyst II, in order to obtain a compound of formula ##STR00048## wherein Ar.sup.1 and o are as defined for the polymer comprising at least one unit of formula (1), and (iii) treating a compound of formula (3) as obtained in step (ii) with a Y.sup.1-donor agent, wherein Y.sup.1 is I, Br, Cl or O—S(O).sub.2CF.sub.3, in order to obtain the compound of formula ##STR00049## wherein Ar.sup.1 and o are as defined for the polymer comprising at least one unit of formula (1), and Y.sup.1 is at each occurrence I, Br, Cl or O—S(O).sub.2CF.sub.3, (iv) treating a compound of formula (2) as obtained in step (iii) with a compound of formula ##STR00050## wherein Ar.sup.2 and n are as defined for the polymer comprising at least one unit of formula (1), and Z.sup.a is at each occurrence selected from the group consisting of B(OZ.sup.1)(OZ.sup.2), SnZ.sup.1Z.sup.2Z.sup.3, ##STR00051## wherein Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6 are independently from each other and at each occurrence H or C.sub.1-6-alkyl, in the presence of catalyst I, in order to obtain the polymer comprising at least one unit of formula (1).

8. A process for the preparation of a compound of ##STR00052## wherein Y.sup.2 is I, Br, Cl or O—S(O).sub.2CF.sub.3, which said process comprises the step of comprising treating a compound of formula ##STR00053## wherein Y.sup.2 is as defined for the compound of formula (4) with an S-donor agent.

9. The compound of ##STR00054## wherein Y.sup.2 is I, Br, Cl or O—S(O).sub.2CF.sub.3.

Description

[0149] FIG. 1 shows the transfer curves measured at various drain voltages V.sub.DS of a bottom-gate, bottom-contact field effect transistor comprising polymer Pa as semiconductor.

EXAMPLE 1

Preparation of Compound 4a

[0150] ##STR00037##

Preparation of Compound 5a

[0151] Compound 6 (1g, 6.32 mmol) was dissolved in methanol (110 mL) under argon atmosphere, potassium bromide was added and the mixture was cooled down to 0° C. Hydrobromic acid (62 wt %, 2,01 eq, 12.68 mmol, 1,12 mL) was added dropwise, followed by dropwise addition of tertbutylhydroperoxide 70 wt % (4.01 eq., 25.37 mmol, 0.55 mL). The addition of hydrogen peroxide was repeated two to three times after stirring at room temperature for 24 hours each time. The reaction was continuously monitored by FD-MS and .sup.1H-NMR spectroscopy. After completion of the reaction, the crude product was filtered off, washed with methanol and the solid residue was subjected to soxhlet-extraction with DCM for 5 days. After precipitation from DCM the compound 5a was obtained as a pale red solid. Yield: 1.176 g, 3.72 mmol, 59%. .sup.1H-NMR: δ (300 MHz, DMSO-d.sup.6)=6.42 (s, 4H). .sup.13C-NMR: δ (300 MHz, DMSO-d.sup.6)=105.94, 105.99, 116.33, 136.88. FD-MS: m/z=315.4 (calc. 315.9). HRMS (ESI): 316.8919 (MH.sup.+); Calcd. for C.sub.8H.sub.5N.sub.4Br.sub.2: 316.9595.

Preparation of Compound 4a

[0152] Compound 5a (1,51 g, 5.18 mmol) was stirred in 60 mL freshly distilled thionyl chloride under argon atmosphere for 18 h at 55° C. The reaction mixture was poured into a mixture of half-concentrated solution of potassium carbonate and ice. The aqueous phase was extracted three times with ethyl acetate. The combined organic layers were dried with magnesium sulfate and the solvent was evaporated. The crude products were purified by column chromatography (dichloromethane: hexane, v:v=1:1) to yield 915.9 mg, (2.680 mmol, 52%) of compound 4a as an orange solid. .sup.13C-NMR: δ (300 MHz, CD.sub.2Cl.sub.2)=114.88, 118.30, 123.50, 154.06. FD-MS: m/z=343.5 (calc. 343.8). HRMS (ESI): 366.8118 (MNa.sup.+); Calcd. for C.sub.8N.sub.4Br.sub.2SNa: 366.9751.

EXAMPLE 2

Preparation of Compound 3a

[0153] ##STR00038##

[0154] Compound 4a (400 mg, 1.163 mmol) and tributyl(4-hexadecylthiophen-2-yl)stannane (62,5% solution 2.053 g, 2.442 mmol) were dissolved in 15 mL o-dichlorobenzene and the solution was degassed through bubbling with argon for 15 minutes. Tetrakis(triphenylphosphine)palladium(0) (268.7 mg, 0.233 mmol) was added and the solution was stirred at 130° C. for 48 hours. After cooling down to room temperature, the mixture was poured on water, the organic phase was separated and the aqueous phase was extracted two times with dichloromethane. The combined organic phases were dried with sodium sulfate, filtered and the dichloromethane was evaporated. The crude product was purified by column chromatography (hexane: dichloromethane, v:v=2:1) to yield 572.6 mg (0.573 mmol, 49%) of compound 3a as an orange solid.

[0155] .sup.1H-NMR: δ (500 MHz, C.sub.2D.sub.2Cl.sub.4)=0.81 (t, 6H), 1.07-1.47 (m, 52H), 1.65 (p, 6H), 2.66 (t, 4H) 7.42 (d, 2H), 7.93 (d, 2H). .sup.13C-NMR: δ (500 MHz, C.sub.2D.sub.2Cl.sub.4)=14.13, 22.77, 29.44, 29.46, 29.46, 29.73, 29.82, 30.57, 32.06, 110.93, 116.47, 127.52,133.12, 133.43 134.11, 144.62, 153.66. FD-MS: m/z=798.4 (calc. 798.5). HRMS (ESI): 821.4656 (MNa.sup.+); Calcd. for C.sub.48H.sub.70N.sub.4S.sub.3Na: 821.4660.

EXAMPLE 3

Preparation of Compound 2a

[0156] ##STR00039##

[0157] Compound 3a (320 mg, 0.4 mmol) and NBS (178.1 mg, 1,001 mmol) were dissolved in 150 mL chloroform/acetic acid 4:1 and the solution was degassed through bubbling with argon for 15 minutes. The mixture was stirred for 7 days at room temperature, while being monitored by thin-layer chromatography. Additional 0.5 (35.62 mg, 0.2 mmol), 1 (71.23 mg, 0.4 mmol) and 2 (142.47 mg, 0.8 mmol) equivalents of NBS had been added after 1, 2 and 5 days respectively. After completion of the reaction, the mixture was poured on water, the aqueous phase was extracted two times with dichloromethane. The combined organic phases were dried with sodium sulfate, filtered and the solvent was evaporated. The crude product was purified by column chromatography (hexane: dichloromethane, v:v=2:1) to yield 355.1 mg (0.371 mmol, 93%) of compound 2a as an red solid. .sup.1H-NMR: δ (300 MHz, CD.sub.2Cl.sub.2)=0.87 (t, 6H), 1.37 (m, 52H), 1.68 (p, 4H), 2.70 (t, 4H), 7.97 (s, 2H). .sup.13C-NMR: δ (300 MHz, CD.sub.2Cl.sub.2)=14.45, 23.27, 29.74, 29.94, 29.97, 30.03, 30.15, 30.23, 30.27, 32.50, 110.71, 116.89, 118.46, 132.38, 133.36, 133.80, 143.97, 153.46. FD-MS: m/z=956.3 (calc. 956.3).

EXAMPLE 4

Preparation of Polymer Pa

[0158] ##STR00040##

[0159] Compound 2a (200 mg, 0.209 mmol), 5,5′-bis(trimethylstannyl)-2,2′-bithiophene (102.8 mg,0.209 mmol) and tri(o-tolyl)phosphine (51.3 mg, 0.168 mmol) were dissolved in 25 mL of o-dichlorobenzene and the solution was degassed through bubbling with argon for 30 minutes. Dipalladium-tris(dibenzylideneacetone) (14.5 mg, 0.014 mmol) was added and the solution was stirred at 130° C. for 48 hours. Trimethyl(5-octylthiophen-2-yl)stannane was added and stirring of the solution was continued for 8 hours at 130° C. After adding bromobenzene and stirring for further 12 hours, the mixture was cooled to room temperature. The polymer was precipitated in 250 mL from methanol, filtered, solved in hot chloroform and stirred with BASOLITE® 100 FOR 30 minutes to remove metal salts. After filtration of BASOLITE and precipitation from methanol once again, the crude material was purified by Sohxlet extraction using methanol, ethyl acetate and petrol ether. Polymer Pa was collected and dried under vacuum (192.48 mg, 94%). .sup.1HNMR: δ (500 MHz, C.sub.2D.sub.2Cl.sub.4)=0.79-0.99(m), 1.10-1.64 (m), 5.55-6.50 (m), 7.23-8.01 (m). Gel-permeation chromatography (GPC) analysis against polystyrene standards in 1,2,4-trichlorobenzene (TCB) using refractive index detector (RI-detector) exhibited a number-averaged molecular weight (M.sub.n) of 8.8.Math.10.sup.3 g/mol and a weight-averaged molecular weight (Mw) of 13.9.Math.10.sup.3 g/mol, giving a polydispersity index (PDI) of 1.59. Thermogravimetric analysis (TGA) was performed on the polymer Pa. Pa shows an initial weight loss at 430° C. indicating high thermal stability of the polymer.

EXAMPLE 5

Preparation of Compound 3b

[0160] ##STR00041##

[0161] Compound 4a (300 mg, 0.872 mmol) and 0.55 mL tributyl(thiophen-2-yl)stannane (650.9 mg, 1.744 mmol) were dissolved in 15 mL o-dichlorobenzene and the solution was degassed through bubbling with argon for 15 minutes. Tetrakis(triphenylphosphine)palladium(0) (201.6 mg, 0.174 mmol) was added and the solution was stirred at 130° C. for 48 hours. After cooling down to room temperature, the mixture was poured on water, the organic phase was separated and the aqueous phase was extracted two times with dichloromethane. The combined organic phases were dried with sodium sulfate, filtered and the dichloromethane was evaporated. The crude product was purified by column chromatography (hexane: dichloromethane, v:v=2:1) to yield 136.2 mg (0.389 mmol, 45%) of compound 3b as an orange solid. .sup.1H-NMR: δ (300 MHz, CD.sub.2Cl.sub.2)=7.35 (dd, 2H), 7.83 (dd, 2H), 8.17 (dd, 2H). .sup.13C-NMR: δ (300 MHz, CD.sub.2Cl.sub.2)=111.51, 116.92, 128.32, 132.74, 133.02, 133.75, 133.81, 153.94. FD-MS: m/z=349.5 (calc. 350.0). HRMS (ESI): 372.9664 (MNa.sup.+); Calcd. for C.sub.16H.sub.6N.sub.4S.sub.3Na: 372.9652.

EXAMPLE 6

Preparation of Compound 3c

[0162] ##STR00042##

[0163] Compound 4a (200 mg, 0.581 mmol) and 0.51 mL tributyl(5-octylthiophen-2-yl)stannane (593.7 mg, 1.221 mmol) were dissolved in 10 mL o-dichlorobenzene and the solution was degassed through bubbling with argon for 15 minutes. Tetrakis(triphenylphosphine)palladium(0) (134.4 mg, 0.116 mmol) was added and the solution was stirred at 130° C. for 48 hours. After cooling down to room temperature, the mixture was poured on water, the organic phase was separated and the aqueous phase was extracted two times with dichloromethane. The combined organic phases were dried with sodium sulfate, filtered and the dichloromethane was evaporated. The crude product was purified by column chromatography (hexane: dichloromethane, v:v=2:1) to yield 129.7 mg (0.226 mmol, 39%) of compound 3c as an red solid.

EXAMPLE 7

Preparation of a Bottom-Gate, Bottom-Contact Field Effect Transistor Comprising Polymer Pa as Semiconductor

[0164] The source and drain electrodes with 60 nm in thickness were deposited by Au evaporation. The channel lengths and widths are 20 and 1400 μm, respectively. A 300 nm thick SiO.sub.2 dielectric covering the highly doped Si acting as the gate electrode was functionalized with hexamethyldisilazane (HMDS) to minimize interfacial trapping sites. Polymer Pa thin films were deposited by drop-casting 2 mg mL.sup.−1 of a solution of polymer Pa in 1,2 dichlorobenzene on the hot field effect transistor precursor (100° C.) in nitrogen atmosphere, followed by annealing at 120° C. for 30 min. The channel lengths and widths are 20 and 1400 μm, respectively.

[0165] Electrical measurements were performed using Keithley 4200 SCS in a glove-box under nitrogen atmosphere.

[0166] The transfer curves measured at various drain voltages V.sub.DS are depicted in FIG. 1.

[0167] The field effect mobility was calculated from the transfer curves in the saturation regime using the equation:

[00001]${\mu }_{\mathrm{FET}}=\frac{2.Math.L}{{\mathrm{WC}}_i}.Math.{\alpha }^2,\alpha =\frac{\partial \surd I_{\mathrm{DS}}}{\partial \surd V_{\mathrm{GS}}}$

where: L denotes the channel length; W denotes the channel width; C.sub.i denotes the capacitance per unit area; IDS denotes the drain source current; VGS denotes the gate voltage; and a denotes the slope obtained by linear fitting of plots of the square-root of the drain current versus the gate voltage (V.sub.GS).

[0168] The ambipolar behaviour of Pa is clearly evident from the output characteristic in both p- and n-type operation modes for negative and positive gate voltages with mobility of 6×10.sup.−4 cm.sup.2 V.sup.−1 s.sup.−1 for holes and 1×10.sup.−4 cm.sup.2 V.sup.−1 s.sup.−1 for electrons.