INDACENO DERIVATIVES AS ORGANIC SEMICONDUCTORS

Abstract

The present invention provides compounds comprising at least one unit of formula (1) or (1′) as well as a process for the preparation of the compounds, intermediates of this process, electronic devices comprising the compounds, and the use of the compounds as semiconducting materials.

##STR00001##

Claims

1. Compounds comprising at least one unit of formula ##STR00078## wherein M1 and M2 are independently of each other an aromatic or heteroaromatic monocyclic or bicyclic ring system; X is at each occurrence O, S, Se or Te, Q is at each occurrence C, Si or Ge, R.sup.1 is at each occurrence selected from the group consisting of H, C.sub.1-50-alkyl, —[CH.sub.2].sub.o—[OSiR.sup.aR.sup.a].sub.p—OSiR.sup.aR.sup.aR.sup.a, —[CH.sub.2].sub.o—[R.sup.aR.sup.aSi—O].sub.p—SiR.sup.aR.sup.aR.sup.a, —[CR.sup.bR.sup.b]q-CR.sup.bR.sup.bR.sup.b, C.sub.2-50- alkenyl, C.sub.2-50-alkynyl, C.sub.5-8-cycloalkyl, C.sub.6-14-aryl and 5 to 14 membered heteroaryl, wherein o is an integer from 0 to 10, p is an integer from 1 to 40, R.sup.a is at each occurrence C.sub.1-10-alkyl, C.sub.2-40-alkenyl or C.sub.2-10-alkynyl, q is an integer from 1 to 50, R.sup.b is at each occurrence H or halogen, with the provisio that not all R.sup.b in —[CR.sup.bR.sup.b].sub.q—CR.sup.bR.sup.bR.sup.b are H, C.sub.1-50-alkyl, C.sub.2-50-alkenyl and C.sub.2-50-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR.sup.c, OC(O)—R.sup.c, C(O)OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)—NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, CN, —SiR.sup.cR.sup.cR.sup.c and NO.sub.2, C.sub.5-8-cycloalkyl can be substituted with one or two substituents independently selected from the group consisting of C.sub.1-10-alkyl, C.sub.2-40-alkenyl, C.sub.2-40-alkynyl, OR.sup.c, OC(O)—R.sup.c, C(O)—OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)—NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, halogen, CN, —SiR.sup.cR.sup.cR.sup.c and NO.sub.2; and one CH.sub.2-group of C.sub.5-8-cycloalkyl can be replaced by O, S, OC(O), CO, NR.sup.c or NR.sup.c—CO, C.sub.6-14-aryl and 5 to 14 membered heteroaryl can be substituted with one to three substituents independently selected from the group consisting of C.sub.1-10-alkyl, C.sub.2-10-alkenyl, C.sub.2-40-alkynyl, OR.sup.c, OC(O)—R.sup.c, C(O)—OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, halogen, CN, and NO.sub.2, wherein R.sup.c is at each occurrence H, C.sub.1-20-alkyl, C.sub.2-40-alkenyl or C.sub.2-40-alkynyl, R.sup.2 is at each occurrence H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl or C.sub.2-30-alkynyl or halogen, n is 0, 1, 2, 3 or 4, m is 0, 1, 2, 3 or 4, and L.sup.1 and L.sup.2 are independently from each other and at each occurrence selected from the group consisting of C.sub.6-26-arylene, 5 to 20 membered heteroarylene, ##STR00079## wherein C.sub.6-26-arylene and 5 to 20 membered heteroarylene can be substituted with one to four substituents R.sup.d at each occurrence selected from the group consisting of H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl, C.sub.2-30-alkynyl and halogen, and ##STR00080## can be substituted with one or two substituents at each occurrence selected from the group consisting of R.sup.e, COOR.sup.e and CN, wherein R.sup.e is at each occurrence selected from the group consisting of H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl and C.sub.2-30-alkynyl.

2. The compounds of claim 1 comprising at least one unit of formula ##STR00081## ##STR00082## wherein X, Q, R.sup.1, R.sup.2, L.sup.1, L.sup.2, n and m are as defined in claim 1, Y is at each occurrence O, S, Se or Te, and R.sup.3 is at each occurrence H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl or C.sub.2-30-alkynyl or halogen.

3. The compounds of claim 1, wherein the compound is a polymer.

4. The compounds of claim 1, wherein X is O, S or Se.

5. The compounds of claim 1, wherein Q is C or Si.

6. The compounds of claim 1, wherein R.sup.1 is at each occurrence selected from the group consisting of H, C.sub.1-50-alkyl, —[CH.sub.2].sub.o—[R.sup.aR.sup.aSi—O].sub.p—SiR.sup.aR.sup.aR.sup.a, —[CR.sup.bR.sup.b].sub.qCR.sup.bR.sup.bR.sup.b, C.sub.2-50-alkenyl and C.sub.2-50-alkynyl, wherein o is an integer from 1 to 10, p is an integer from 1 to 40, R.sup.a is at each occurrence C.sub.1-10-alkyl, C.sub.2-40-alkenyl or C.sub.2-10-alkynyl, q is an integer from 1 to 50, R.sup.b is at each occurrence H or halogen, with the provisio that not all R.sup.b in —[CR.sup.bR.sup.b].sub.q—CR.sup.bR.sup.bR.sup.b are H, C.sub.1-50-alkyl, C.sub.2-50-alkenyl and C.sub.2-50-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR.sup.c, OC(O)—R.sup.c, C(O)OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)—NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, CN, and NO.sub.2, wherein R.sup.c is at each occurrence H, C.sub.1-20-alkyl, C.sub.2-40-alkenyl or C.sub.2-40-alkynyl.

7. The compounds of claim 1, wherein R.sup.1 is at each occurrence C.sub.1-50-alkyl.

8. The compounds of claim 1, wherein R.sup.2 is at each occurrence H, C.sub.1-30-alkyl or halogen.

9. The compounds of claim 1, wherein m is 0, 1 or 2.

10. The compounds of claim 1, wherein n is 0.

11. The compounds of claim 1, wherein L.sup.1 and L.sup.2 are independently from each other and at each occurrence consisting of C.sub.6-26-arylene, 5 to 20 membered heteroarylene, and ##STR00083## wherein C.sub.6-26-arylene and 5 to 20 membered heteroarylene can be substituted with one to four substituents R.sup.d at each occurrence selected from the group consisting of C.sub.1-30-alkyl, C.sub.2-30-alkenyl, C.sub.2-30-alkynyl and halogen, wherein C.sub.6-26-arylene, optionally substituted with one to four substituents R.sup.d, is selected from the group consisting of ##STR00084## wherein R.sup.101 is at each occurrence H or C.sub.1-30-alkyl, and wherein 5 to 20 membered heteroarylene, optionally substituted with one to four substitutents R.sup.d, are selected from the group consisting of ##STR00085## ##STR00086## ##STR00087## wherein R.sup.103 is at each occurrence H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl or C.sub.2-30-alkynyl or halogen, R.sup.102 is at each occurrence H or C.sub.1-30-alkyl.

12. A process for the preparation of the compounds of claim 1 comprising at least one unit of formula ##STR00088## wherein M1 and M2 are independently of each other an aromatic or heteroaromatic monocyclic or bicyclic ring system; X is at each occurrence O, S, Se or Te, Q is at each occurrence C, Si or Ge, R.sup.1 is at each occurrence selected from the group consisting of H, C.sub.1-50-alkyl, —[CH.sub.2].sub.o—[OSiR.sup.BR.sup.a].sub.p—OSiR.sup.aR.sup.aR.sup.a, —[CH.sub.2].sub.o—[R.sup.aR.sup.aSi—O].sub.p—SiR.sup.aR.sup.aR.sup.a, —[CR.sup.bR.sup.b]q-CR.sup.bR.sup.bR.sup.b, C.sub.2-50-alkenyl, C.sub.2-50-alkynyl, C.sub.5-8-cycloalkyl, C.sub.6-14-aryl and 5 to 14 membered heteroaryl, wherein is an integer from 0 to 10, p is an integer from 1 to 40, R.sup.a is at each occurrence C.sub.1-10-alkyl, C.sub.2-40-alkenyl or C.sub.2-10-alkynyl, q is an integer from 1 to 50, R.sup.b is at each occurrence H or halogen, with the provisio that not all R.sup.b in —[CR.sup.bR.sup.b].sub.q—CR.sup.bR.sup.bR.sup.b are H, C.sub.1-50-alkyl, C.sub.2-50-alkenyl and C.sub.2-50-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR.sup.c, OC(O)—R.sup.c, C(O)OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)—NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, CN, —SiR.sup.cR.sup.cR.sup.c and NO.sub.2, C.sub.5-8-cycloalkyl can be substituted with one or two substituents independently selected from the group consisting of C.sub.1-10-alkyl, C.sub.2-40-alkenyl, C.sub.2-40-alkynyl, OR.sup.c, OC(O)—R.sup.c, C(O)—OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)—NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, halogen, CN, —SiR.sup.cR.sup.cR.sup.c and NO.sub.2; and one CH.sub.2-group of C.sub.5-8-cycloalkyl can be replaced by O, S, OC(O), CO, NR.sup.c or NR.sup.c—CO, C.sub.6-14-aryl and 5 to 14 membered heteroaryl can be substituted with one to three substituents independently selected from the group consisting of C.sub.1-10-alkyl, C.sub.2-10-alkenyl, C.sub.2-40-alkynyl, OR.sup.c, OC(O)—R.sup.c, C(O)—OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, halogen, CN, and NO.sub.2, wherein R.sup.c is at each occurrence H, C.sub.1-20-alkyl, C.sub.2-40-alkenyl or C.sub.2-40-alkynyl, R.sup.2 is at each occurrence H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl or C.sub.2-30-alkynyl or halogen, n is 0, 1, 2, 3 or 4, m is 0, 1, 2, 3 or 4, and L.sup.1 and L.sup.2 are independently from each other and at each occurrence selected from the group consisting of C.sub.6-26-arylene, 5 to 20 membered heteroarylene, ##STR00089##  wherein  C.sub.6-26-arylene and 5 to 20 membered heteroarylene can be substituted with one to four substituents R.sup.d at each occurrence selected from the group consisting of H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl, C.sub.2-30-alkynyl and halogen, and ##STR00090##  and can be substituted with one or two substituents at each occurrence selected from the group consisting of R.sup.e, COOR.sup.e and CN, wherein R.sup.e is at each occurrence selected from the group consisting of H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl and C.sub.2-30-alkynyl, which process comprises the step of treating a compound of formula ##STR00091## wherein M1, M2, X, Q, R.sup.1 and R.sup.2 are as defined for units of formula 1 and 1′, with acid to afford a compound of formula ##STR00092## wherein M1, M2, X, Q, R.sup.1 and R.sup.2 are as defined for the units of formula 1 and 1′.

13. Compounds of formula ##STR00093## wherein M1 and M2 are independently of each other an aromatic or heteroaromatic monocyclic or bicyclic ring system; X is at each occurrence O, S, Se or Te, Q is at each occurrence C, Si or Ge, R.sup.1 is at each occurrence selected from the group consisting of H, C.sub.1-50-alkyl, —[CH.sub.2].sub.o—[OSiR.sup.aR.sup.a].sub.p—OSiR.sup.aR.sup.aR.sup.a, —[CH.sub.2].sub.o—[R.sup.aR.sup.aSi—O].sub.p—SiR.sup.aR.sup.aR.sup.a, —[CR.sup.bR.sup.b]q-CR.sup.bR.sup.bR.sup.b, C.sub.2-50-alkenyl, C.sub.2-50-alkynyl, C.sub.5-8-cycloalkyl, C.sub.6-14-aryl and 5 to 14 membered heteroaryl, wherein is an integer from 0 to 10, p is an integer from 1 to 40, R.sup.a is at each occurrence C.sub.1-10-alkyl, C.sub.2-40-alkenyl or C.sub.2-10-alkynyl, q is an integer from 1 to 50, R.sup.b is at each occurrence H or halogen, with the provisio that not all R.sup.b in —[CR.sup.bR.sup.b].sub.q—CR.sup.bR.sup.bR.sup.b are H, C.sub.1-50-alkyl, C.sub.2-50-alkenyl and C.sub.2-50-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR.sup.c, OC(O)—R.sup.c, C(O)OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)—NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, CN, —SiR.sup.cR.sup.cR.sup.c and NO.sub.2, C.sub.5-8-cycloalkyl can be substituted with one or two substituents independently selected from the group consisting of C.sub.1-10-alkyl, C.sub.2-40-alkenyl, C.sub.2-40-alkynyl, OR.sup.c, OC(O)—R.sup.c, C(O)—OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)—NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, halogen, CN, —SiR.sup.cR.sup.cR.sup.c and NO.sub.2; and one CH.sub.2-group of C.sub.5-8-cycloalkyl can be replaced by O, S, OC(O), CO, NR.sup.c or NR.sup.c—CO, C.sub.6-14-aryl and 5 to 14 membered heteroaryl can be substituted with one to three substituents independently selected from the group consisting of C.sub.1-10-alkyl, C.sub.2-10-alkenyl, C.sub.2-40-alkynyl, OR.sup.c, OC(O)—R.sup.c, C(O)—OR.sup.c, C(O)—R.sup.c, NR.sup.cR.sup.c, NR.sup.c—C(O)R.sup.c, C(O)NR.sup.cR.sup.c, N[C(O)R.sup.c][C(O)R.sup.c], SR.sup.c, halogen, CN, and NO.sub.2, wherein R.sup.c is at each occurrence H, C.sub.1-20-alkyl, C.sub.2-40-alkenyl or C.sub.2-40-alkynyl, R.sup.2 is at each occurrence H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl or C.sub.2-30-alkynyl or halogen.

14. Compounds of claim 13 which are of formula ##STR00094## ##STR00095## wherein X, Q, R.sup.1 and R.sup.2 are as defined in claim 13, and Y is at each occurrence O, S, Se or Te, and R.sup.3 is at each occurrence H, C.sub.1-30-alkyl, C.sub.2-30-alkenyl or C.sub.2-30-alkynyl or halogen.

15.-17. (canceled)

Description

[0246] FIG. 1 shows the transfer characteristics of an organic field effect transistor comprising polymer P1 as semiconducting material

[0247] FIG. 2 shows the output characteristics of an organic field effect transistor comprising polymer P1 as semiconducting material.

EXAMPLES

Example 1

[0248] Preparation of Compound 11a

##STR00074##

[0249] Compound 13a: A solution of LDA in THF (1 M) (67.4 mL, 67.4 mmol) was added dropwise to 3-bromothiophene (14a) (10 g, 61.3 mmol) in 300 mL THF at 0° C. After stirring the mixture for 1 h, DMF (5.2 mL, 67.4 mmol) was added to the mixture at 0° C. and the mixture was warmed up to room temperature. After stirring for 4 h, water (100 mL) was added to the mixture and it was extracted with ether for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/ethyl acetate (50:1) as eluent to give compound 13a as a yellow oil. Yield: 11.0 g (94%). .sup.1H NMR (400 MHz; CDCl.sub.3): δ 7.15 (d, 1H, J=4.8 Hz), 7.73 (dd, 1H, J=1.2, 5.2 Hz), 9.98 (d, 1H, J=1.2 Hz); .sup.13C NMR (100 MHz; CDCl.sub.3): δ 120.38, 132.03, 134.87, 136.90, 183.03.

[0250] Compound 12a: 3-bromothiophene-2-carbaldehyde(13a) (11 g, 57.6 mmol) was dissolved in methanol (300 ml) and cooled to 0° C. NaBH.sub.4 (3.3 g, 86.4 mmol) was added in small portions to the mixture and stirred for 4 h. Water (100 mL) was added to the mixture and it was extracted with ether for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/ethyl acetate (10:1) as eluent to give compound 12a as a colourless oil. Yield: 10.9 g (98%). .sup.1H NMR (700 MHz, CDCl.sub.3) δ 7.28 (d, 1H, J=5.2 Hz), 6.98 (d, 1H, J=5.2 Hz), 4.83 (d, 2H, J=6.4 Hz), 2.98 (s, br, 1H); .sup.13C NMR (176 MHz, CDCl.sub.3) δ 138.31, 130.13, 125.48, 108.89, 58.96.

[0251] Compound 11a: Imidazole (8.82 g, 129.5 mmol) was added to a solution of (3-bromothiophen-2-yl)methanol (12a) (10 g, 51.8 mmol) and triisopropylchlorosilane (11.98 g, 62.16 mmol) in dichloromethane. The mixture was stirred for 12 h, diluted with saturated aq. NH4Cl, extracted with EtOAc, washed with brine and concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluent: Petroleum ether/ethyl acetate=50:1) to provide compound 11a as a colorless solid (17.74 g, 98% yield). .sup.1HNMR (700 MHz, CDCl.sub.3) δ 7.21 (d, J=5.3 Hz, 1H), 6.92 (d, J=5.3 Hz, 1H), 4.92 (s, 2H), 1.22-1.18 (m, 3H), 1.12 (s, 18H); .sup.13CNMR (176 MHz, CDCl.sub.3) δ 140.83, 129.60, 124.39, 105.30, 61.23, 18.01, 12.01.

Example 2

[0252] Preparation of Polymer P1 Comprising a Unit of Formula 1A

##STR00075## ##STR00076## ##STR00077##

[0253] Compound 10a and compound 9a were synthesized as described in W. Zhang, J. Smith, S. E. Watkins, R. Gysel, M. McGehee, A. Salleo, J. Kirkpatrick, S. Ashraf, T. Anthopoulos, M. Heeney, I. McCulloch, J. Am. Chem. Soc. 2010, 132, 11437.

[0254] Compound 8a: 4,4,9,9-tetrahexadecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene (9a) (10 g, 8.59 mmol) was dissolved in anhydrous THF (100 mL) and cooled down to −78′ C under argon, n-butyllithium solution (2.5M, 8.59 mL) was added dropwise and the mixture was warmed up to 0° C. and stirred for 30 min. The mixture was cooled down to −78° C. again and then 1 mL of DMF was added dropwise into the solution and the mixture was warmed up to room temperature and stirred for another 6 hours. Water (100 mL) was added to the mixture and it was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/ethyl acetate (5:1) as eluent to give compound 8a as a yellow solid (9.75 g, 93% yield). .sup.1H NMR (500 MHz, CDCl.sub.3) δ 9.94 (s, 1H), 7.66 (s, 1H), 7.48 (s, 1H), 2.12-2.10 (m, 8H), 1.36-0.92 (m, 104H), 0.91-0.87 (m, 12H), 0.82-0.65 (m, 8H); .sup.13C NMR (126 MHz, CDCl.sub.3) δ 182.96, 156.06, 155.18, 151.40, 145.60, 136.47, 130.41, 115.03, 53.81, 39.12, 32.11, 30.12, 29.84, 29.76, 29.43, 24.32, 22.81, 14.22.

[0255] Compound 7a: (3-bromothiophen-2-yl)methoxy)triisopropylsilane (11a) (5 g, 14.3 mmol), prepared as described in example 1, was dissolved in 100 mL anhydrous diethyl ether and cooled to −78° C., n-Butyllithium solution (2.5M, 5.72 mL) was added dropwise stirred for 30 min. 4,4,9,9-tetrahexadecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-dicarbaldehyde (8a) (5.82 g, 4.76 mmol) dissolved in 50 mL anhydrous diethyl ether was added dropwise into the solution and stirred for further 30 min. The mixture was warmed up to room temperature and stirred overnight. Water (150 mL) was added to the mixture and it was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/dichloromethane (3:1) as eluent to give compound 7a as a brown liquid (6.04 g, 72% yield). .sup.1H NMR (700 MHz, CDCl.sub.3) δ 7.26 (s, 2H), 7.16 (s, 2H), 7.14 (d, J=5.2 Hz, 2H), 7.03 (d, J=5.2 Hz, 2H), 6.17 (d, J=4.8 Hz, 2H), 4.97 (s, 4H), 2.15-2.10 (m, 8H), 1.23-1.14 (m, 6H), 1.34-0.97 (m, 140H), 0.91-0.82 (m, 12H), 0.81-0.65 (m, 8H); .sup.13C NMR (176 MHz, CDCl.sub.3) δ 171.19, 154.24, 152.54, 148.90, 145.69, 141.11, 140.71, 139.54, 135.67, 128.11, 126.40, 124.23, 123.09, 122.98, 119.11, 112.79, 60.43, 31.96, 29.76, 29.71, 29.41, 22.73, 21.08, 18.03, 18.01, 17.99, 17.73, 14.22, 14.16, 12.02, 11.95.

[0256] Compound 6a: Compound 7a (10.87 g, 6.17 mmol) was dissolved in 100 mL dichloromethane and then ZnI.sub.2 (0.40 g, 1.24 mmol) was added in one portion, followed by the addition of NaBH.sub.3CN (1.17 g, 18.52 mmol). The mixture was stirred overnight and then quenched by Water (100 mL). The mixture was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane as eluent to give compound 6a as a yellow liquid (10.04 g, 94% yield).

[0257] .sup.1H NMR (700 MHz, CDCl.sub.3) δ 7.26 (s, 2H), 7.14 (d, J=5.1 Hz, 2H), 6.87 (d, J=5.1 Hz, 2H), 6.65 (s, 2H), 4.96 (s, 4H), 4.14 (s, 4H), 2.15-2.10 (m, 8H), 1.28-1.14 (m, 6H), 1.34-0.96 (m, 140H), 0.91-0.85 (m, 12H), 0.82-0.64 (m, 8H); .sup.13C NMR (176 MHz, CDCl.sub.3) δ 154.43, 152.29, 145.05, 139.98, 139.90, 135.51, 134.85, 129.04, 126.84, 123.09, 121.23, 119.68, 112.50, 59.59, 41.36, 39.07, 36.09, 31.96, 29.75, 27.70, 24.24, 22.73, 20.48, 18.62, 17.85, 14.17, 12.97, 11.48.

[0258] Compound 5a: Compound 6a (5.58 g, 3.23 mmol) was dissolved in 100 mL THF and TBAF (1M in THF, 8.07 mL) was added into the solution and the mixture was stirred overnight and then quenched by Water (100 mL). The mixture was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/dichloromethane (1:1) as eluent to give compound 5a as a yellow liquid (4.35 g, 95% yield). .sup.1H NMR (700 MHz, CDCl.sub.3) δ 7.26 (s, 2H), 7.21 (d, J=5.1 Hz, 2H), 6.93 (d, J=5.1 Hz, 2H), 6.69 (s, 2H), 4.83 (s, 4H), 4.21 (s, 4H), 2.14-2.12 (m, 8H), 1.32-0.97 (m, 104H), 0.91-0.84 (m, 12H), 0.82-0.64 (m, 8H); .sup.13C NMR (176 MHz, CDCl.sub.3) δ 171.26, 154.54, 152.31, 145.13, 140.06, 137.83, 137.71, 135.49, 129.52, 124.29, 119.71, 112.55, 60.46, 57.78, 53.94, 39.07, 31.96, 30.08, 29.75, 29.71, 29.69, 29.46, 29.41, 24.23, 22.73, 21.09, 17.73, 14.22, 14.17, 12.29.

[0259] Compound 4a: Compound 5a (5.22 g, 3.68 mmol) was dissolved in 100 mL dichloromethane and Dess-Martin periodinane (3.91 g, 9.22 mmol) was added into the solution and the mixture was stirred overnight and then slowly quenched by saturated NaHCO.sub.3 solution. The mixture was stirred at room temperature for 30 min and then saturated NaS.sub.2SO.sub.3 solution was added. The mixture was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/dichloromethane (1:1) as eluent to give compound 4a as a yellow solid (4.52 g, 87% yield). .sup.1H NMR (700 MHz, CDCl.sub.3) δ 10.13 (s, 2H), 7.65 (d, J=5.0 Hz, 2H), 7.14 (s, 2H), 7.05 (d, J=5.0 Hz, 2H), 6.74 (s, 2H), 4.56 (s, 4H), 2.13-2.11 (m, 8H), 1.36-0.96 (m, 104H), 0.90-0.86 (m, 12H), 0.83-0.69 (m, 8H); .sup.13C NMR (176 MHz, CDCl.sub.3) δ 182.09, 154.69, 152.44, 149.14, 143.00, 141.50, 140.61, 137.85, 135.50, 134.50, 131.27, 131.08, 128.42, 128.26, 53.93, 39.01, 31.90, 30.25, 29.71, 29.73, 29.63, 29.41, 29.49, 24.22, 22.71, 21.39, 17.43, 14.12, 14.10, 12.49.

[0260] Compound 3a: 3,3′-((4,4,9,9-tetrahexadecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methylene))bis(thiophene-2-carbaldehyde) (4a) (3.77 g, 2.67 mmol) was dissolved in 100 mL toluene and 5 g Amberlyst-15 was added into the solution and the mixture was refluxed overnight and the water generated in situ was removed by a Dean-Stark Trap. The mixture was filtered, and the filtrate was concentrated under vacuum. The crude product was purified by column chromatography on silica gel with hexane as eluent to give compound 3a as a pale yellow solid (2.28 g, 62% yield). .sup.1H NMR (700 MHz, CD.sub.2Cl.sub.2) δ 8.37 (s, 2H), 8.31 (s, 2H), 7.52 (s, 2H), 7.51 (d, J=5.3 Hz, 2H), 7.41 (d, J=5.4 Hz, 2H), 2.13-2.11 (m, 8H), 1.34-0.96 (m, 104H), 0.91-0.86 (m, 12H), 0.82-0.69 (m, 8H); .sup.13C NMR (176 MHz, CD.sub.2Cl.sub.2). 13C NMR (176 MHz, CDCl3) δ 139.07, 131.37, 127.83, 126.75, 122.52, 122.09, 121.64, 117.43, 111.44, 108.12, 103.46, 99.16, 98.40, 40.43, 24.10, 16.91, 14.67, 14.65, 14.64, 14.61, 14.58, 14.46, 14.35, 14.17, 8.78, 7.68, 0.90.

[0261] Compound 2a: Compound 3a (3.42 g, 2.49 mmol) was dissolved in 80 mL THF and cooled to −78° C., n-butyllithium solution (2.5M, 2.49 mL) was added dropwise stirred for 30 min. 6.23 mL Me.sub.3SnCl solution (1M in THF) was added dropwise into the solution and the mixture was warmed up to room temperature and stirred overnight and then quenched by water (80 mL). The mixture was extracted with ethyl acetate for three times. The organic phases were collected, concentrated under vacuum. The product was recrystallized in acetonitrile/dichloromethane to afford compound 2a as a pale yellow solid. (4.02 g, 95% yield). .sup.1H NMR (500 MHz, CD.sub.2Cl.sub.2) δ 8.36 (s, 1H), 8.32 (s, 2H), 7.53 (s, 2H), 7.50 (s, 2H), 2.53-2.34 (m, 4H), 2.34-2.16 (m, 4H), 1.41-0.95 (m, 104H), 0.93-0.86 (m, 12H), 0.84-0.61 (m, 8H) 0.50 (s, 18H).

[0262] Polymer P1: A 2.5 mL microwave vial was charged with compound 2a (0.40 g, 0.233 mmol), 4,7-dibromobenzo[c][1,2,5]thiadiazole (0.068 g, 0.233 mmol), 2 mol % of tris(dibenzylideneacetone)dipalladium (2.9 mg, 0.005 mmol) and tri(o-tolyl) phosphine (6 mg, 0.02 mmol). The vial was sealed and chlorobenzene (1 mL) was added. The obtained solution was degassed with argon for 30 minutes. The vial was subjected to the following reaction conditions in the microwave reactor: 2 minutes at 100° C., 2 minutes at 120° C., 5 minutes at 140° C., 5 minutes at 160° C. and 20 minutes at 180° C. The polymer was endcapped by addition of 0.1 eq. of 2-bromobenzene before the reaction mixture was resubmitted to the microwave reactor, 1 minute at 100° C., 1 minute at 120° C., 2 minutes at 140° C. and 5 minutes at 160° C. The polymeric solution was cooled down and 0.1 eq. of 2-(trimethylstannyl)benzene was added by syringe. The reaction vial was subjected to the previously mentioned temperature scheme to finalize the end-capping reaction. After reaction, the crude polymer was precipitated in methanol and then further purified by Soxhlet extractions with acetone, hexane and chloroform for 24 hours each. Remaining palladium residues were removed by treating a polymeric chloroform solution with an aqueous sodium diethyldithiocarbamate solution for 2 hours at 50° C. under vigorous stirring. Afterwards the organic phase was separated from the aqueous phase and washed several times with water. The polymeric solution was concentrated under reduced pressure and precipitated into cold methanol. Polymer P1 was filtered off and dried under high vacuum for at least 24 hours. .sup.1H NMR (500 MHz, CDCl.sub.3) δ 8.71 (br, 2H), 8.37 (br, 2H), 8.13 (br, 2H), 7.68 (br, 2H), 7.74 (br, 2H), 2.14-2.10 (br, 8H), 0.95-1.32 (br, 104H), 0.91-0.84 (br, 12H), 0.82-0.61 (br, 8H).

Example 3

[0263] Preparation of a Bottom-Contact, Top-Gate Organic Fieldeffect Transistor (OFET) Comprising Polymer P1 as Semiconducting Material

[0264] Gold source and drain contacts were evaporated on glass, followed by treatment with pentafluorobenzenethiol. The semiconducting layer was then spin-coated from 10 mg mL.sup.−1 solution of polymer P1 in chlorobenzene and Cytop®, a commercially available fluoropolymer, was deposited as gate dielectric. An Ag gate electrode was used. The channel width and length are W=1000 μm and L=30 μm.

[0265] The transfer and output characteristics of the OFET were measured.

[0266] FIGS. 1 and 2 show the transfer and output characteristics of the OFET.

[0267] Field effect mobility was calculated using the standard thin film transistor model in the saturation regime of the device using:

[00001]${\mu }_{\mathrm{sat}}=\frac{2L}{\mathrm{WC}}.Math.{\left(\frac{\partial I_{\mathrm{dsat}}}{\partial V_g}\right)}^2,$

where L, W, and C are the channel length, channel width, and capacitance of the dielectric, respectively.

[0268] The average saturation hole mobility of the OFET was 2.5 cm.sup.2 V.sup.−1 s.sup.−1, with an on/off ratio of 2×10.sup.5 and approximately −17 V threshold voltage.