Heteroacene compounds for organic electronics

Abstract

The present invention provides compounds of formula (1) wherein o is 1, 2 or 3, p is 0, 1 or 2, n is 0, 1 or 2, m is 0, 1 or 2, and A is a mono- or polycyclic ring system, which may contain at least one heteroatom, and an electronic device comprising the compounds as semiconducting material. ##STR00001##

Claims

1. A compound of formula (1) ##STR00027## wherein o is 1, 2 or 3, p is 0, 1 or 2, n is 0, 1 or 2, m is 0, 1 or 2, A is a mono -or dicyclic ring system A, which contains at least S atom, wherein R.sup.10 is at each occurrence C.sub.1-30-alkyl, wherein at least one CH.sub.2-group of C.sub.1-30-alkyl, but not adjacent CH.sub.2-groups, is optionally replaced with —O— or —S—, C.sub.1-30-alkyl is optionally substituted with 1 to 10 R.sup.100 residues at each occurrence selected from the group consisting of halogen, —CN, —NO.sub.2, —OH, —NH.sub.2, —NH(R.sup.a), —N(R.sup.a).sub.2, —NH—C(O)—(R.sup.a), —N(R.sup.a)—C(O)—(R.sup.a), —N[C(O)—(R.sup.a)].sub.2, —C(O)—R.sup.a, —C(O)—OR.sup.a, —C(O)NH.sub.2, —CO(O)NH—R.sup.a, —C(O)N(R.sup.a).sub.2, —O—R.sup.a, —O—C(O)—R.sup.a, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, and wherein R.sup.a is at each occurrence selected from the group consisting of C.sub.1-20-alkyl, C.sub.2-20-alkenyl, C.sub.2-20-alkynyl, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, wherein C.sub.1-20-alkyl, C.sub.2-20-alkenyl and C.sub.2-20-alkynyl are optionally substituted with 1 to 5 residues at each occurrence selected from the group consisting of halogen, CN, —NO.sub.2, —OH, —NH.sub.2, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system; R.sup.3 and R.sup.11 are independently from each other at each occurrence selected from the group consisting of halogen, —CN, —NO.sub.2, C.sub.1-30-alkyl, C.sub.2-30-alkenyl, C.sub.2-30-alkynyl, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, wherein at least one CH.sub.2-group of CH.sub.1-30-alkyl, C.sub.2-30-alkenyl and C.sub.2-30-alkynyl, but not adjacent CH.sub.2-groups, is optionally replaced with —O— or —S—, and C.sub.1-30-alkyl, C.sub.2-30-alkenyl and C.sub.2-30-alkynyl are optionally substituted with 1 to 10 R.sup.101 residues independently selected from the group consisting of halogen, —CN, —NO.sub.2, —OH, —NH.sub.2, —NH(R.sup.b), —N(R.sup.b).sub.2, —NH—C(O)—(R.sup.b), —N(R.sup.b)—C(O)—(R.sup.b), —N[C(O)—(R.sup.b)].sub.2, —C(O)—R.sup.b, —C(O)—OR.sup.b, —C(O)NH.sub.2, —CO(O)NH—R.sup.b, —C(O)N(R.sup.b).sub.2, —O—R.sup.b, —O—C(O)—R.sup.b, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, and wherein R.sup.b is at each occurrence selected from the group consisting of C.sub.1-20-alkyl, C.sub.2-20-alkenyl, C.sub.2-20-alkynyl, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, wherein C.sub.1-20-alkyl, C.sub.2-20-alkenyl or C.sub.2-20-alkynyl are optionally substituted with 1 to 5 residues at each occurrence selected from the group consisting of halogen, CN, —NO.sub.2, —OH, —NH.sub.2, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, and C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system are optionally substituted with 1 to 5 residues independently selected from the group consisting of halogen, CN, —NO.sub.2, —OH, —NH.sub.2, C.sub.1-10-alkyl, C.sub.2-10-alkenyl, and C.sub.2-10-alkynyl.

2. The compound of claim 1, wherein A is ##STR00028##

3. The compound of claim 1, wherein R.sup.10 is at each occurrence C.sub.8-20-alkyl.

4. The compound of claim 1, wherein R.sup.3 and R.sup.11 are independently from each other at each occurrence selected from the group consisting of halogen, —CN, C.sub.1-30-alkyl, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, wherein at least one CH.sub.2-group of C.sub.1-30-alkyl, but not adjacent CH.sub.2-groups, is optionally replaced with —O— or —S—, and C.sub.1-30-alkyl is optionally substituted with 1 to 10 R.sup.101 residues independently selected from the group consisting of halogen, —CN, —NO.sub.2, —OH, —NH.sub.2, —NH(R.sup.b), —N(R.sup.b).sub.2, —NH—C(O)—(R.sup.b), —N(R.sup.b)—C(O)—(R.sup.b), —N[C(O)—(R.sup.b)].sub.2, —C(O)—R.sup.b, —C(O)—OR.sup.b, —C(O)NH.sub.2, —CO(O)NH—R.sup.b, —C(O)N(R.sup.b).sub.2, —O—R.sup.b, —O—C(O)—R.sup.b, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, and wherein wherein R.sup.b is at each occurrence selected from the group consisting of C.sub.1-20-alkyl, C.sub.2-20-alkenyl, C.sub.2-20-alkynyl, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, wherein C.sub.1-20-alkyl, C.sub.2-20-alkenyl or C.sub.2-20-alkynyl is optionally substituted with 1 to 5 residues at each occurrence selected from the group consisting of halogen, CN, —NO.sub.2, —OH, —NH.sub.2, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, and C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system are optionally substituted with 1 to 5 residues independently selected from the group consisting of halogen, CN, —NO.sub.2, —OH, —NH.sub.2, C.sub.1-10-alkyl, C.sub.2-10-alkenyl, and C.sub.2-10-alkynyl.

5. The compound of claim 1, wherein R.sup.3 and R.sup.11 are independently from each other at each occurrence selected from the group consisting of C.sub.1-30-alkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, wherein at least one CH.sub.2-group of C.sub.1-30-alkyl, but not adjacent CH.sub.2-groups, is optionally replaced with —O— or —S—, and C.sub.1-30-alkyl is optionally substituted with 1 to 10 R.sup.101 residues independently selected from the group consisting of halogen, —CN, —NO.sub.2, —OH, —NH.sub.2, —NH(R.sup.b), —N(R.sup.b).sub.2, —NH—C(O)—(R.sup.b), —N(R.sup.b)—C(O)—(R.sup.b), —N[C(O)—(R.sup.b)].sub.2, —C(O)—R.sup.b, —C(O)—OR.sup.b, —C(O)NH.sub.2, —CO(O)NH—R.sup.b, —C(O)N(R.sup.b).sub.2, —O—R.sup.b, —O—C(O)—R.sup.b, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, and wherein wherein R.sup.b is at each occurrence selected from the group consisting of C.sub.1-20-alkyl, C.sub.2-20-alkenyl, C.sub.2-20-alkynyl, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, wherein C.sub.1-20-alkyl, C.sub.2-20-alkenyl or C.sub.2-20-alkynyl is optionally substituted with 1 to 5 residues at each occurrence selected from the group consisting of halogen, CN, —NO.sub.2, —OH, —NH.sub.2, C.sub.4-8-cycloalkyl, C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system, and C.sub.6-14-aryl, and a 5 to 14 membered heterocyclic ring system are optionally substituted with 1 to 5 residues independently selected from the group consisting of halogen, CN, —NO.sub.2, —OH, —NH.sub.2, C.sub.1-10-alkyl, C.sub.2-10-alkenyl, and C.sub.2-10-alkynyl.

6. The compound of claim 1, wherein o is 1.

7. The compound of claim 1, wherein p, n and m are 0.

8. The compound of claim 1, wherein the compound of formula (1) is selected from the group consisting of formulae (1′a) and (1′b) ##STR00029## wherein R.sup.10 is C.sub.8-20-alkyl.

9. An electronic device comprising the compound according to claim 1.

10. The electronic device of claim 9, wherein the electronic device is an organic field effect transistor (OFET).

11. A method comprising incorporating the compound according to claim 1 as a semiconducting material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the design of the bottom-gate, top-contact organic field effect transistor of example 3.

(2) FIG. 2 shows the drain current I.sub.d [A] in relation to the gate-source voltage V.sub.g [V] (top transfer curve) and the drain current I.sub.d.sup.1/2 [A.sup.1/2] in relation to the gate-source voltage V.sub.g [V] (bottom transfer curve) for the bottom-gate top-contact organic field effect transistor of example 3 comprising compound 1b as semiconducting material at a drain voltage V.sub.d of −60 V.

(3) FIG. 3 shows the drain current I.sub.d [A] in relation to the drain voltage V.sub.d [V] (output curves) for the bottom-gate, top-contact organic field effect transistor of example 3 comprising compound 1b as semiconducting material at a gate-source voltage V.sub.g of −60 V (first and top curve), −40 V (second curve), −20 V (third curve) and 0 V (fourth and bottom curve).

(4) FIG. 4 shows the drain current I.sub.d [A] in relation to the gate-source voltage V.sub.g [V] (top transfer curve) and the drain current I.sub.d.sup.1/2 [10.sup.−3 A.sup.1/2] in relation to the gate-source voltage V.sub.g [V] (bottom transfer curve) for the bottom-gate top-contact organic field effect transistor of example 3 comprising compound 1a as semiconducting material at a drain voltage V.sub.d of −40 V.

(5) FIG. 5 shows the drain current I.sub.d [A] in relation to the drain voltage V.sub.d [V] (output curves) for the bottom-gate, top-contact organic field effect transistor of example 3 comprising compound 1a as semiconducting material at a gate-source voltage V.sub.g of −60 V (first and top curve), −55 V (second curve), −50 V (third curve) and −45 V (fourth and bottom curve).

EXAMPLES

Example 1

(6) Preparation of Compound 1a

(7) ##STR00024##
Preparation of Compound 8a

(8) Commercially available thieno[3,2-b]thiophene (4 g, 32 mmol) in THF (100 mL) was cooled to −78° C. and n-butyllithium solution (1.6 M, 42 mL, 66 mmol) was added drop wise over 60 minutes using a dropping funnel. The reaction mixture was gradually warmed to room temperature and stirred for 3 hrs. The resultant suspension was again cooled to −78° C. and a solution of trimethyltin chloride (13.15 g, 66 mmol) in THF (50 mL) was added drop wise over 30 minutes using a dropping funnel. The resultant mixture was gradually warmed to room temperature and stirred for 16 hrs. The reaction mixture was quenched with water (150 mL) and extracted with Et.sub.2O (2×100 mL). Combined organic layers were washed with brine and concentrated to give brown solids, which were triturated with ethanol (4×20 mL). The solids were collected by filtration and washed thoroughly with ethanol (2×20 mL) to yield compound 8a as a white solid (10 g, 68%), which was used directly in the next step without further purification.

(9) .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.26 (s, 2H), 0.37 (s, 18H).

(10) Preparation of Compound 6a

(11) Commercially available LDA solution (2 M, 24 mL, 47 mmol) was diluted in THF (65 mL) solution at 0° C. A solution of 2-bromo-5-tetradodecyl-thiophene (7a) (14 g, 39 mmol) in THF (65 mL) was added drop wise to the dilute LDA solution at 0° C. over 1 h using a dropping funnel. The resultant mixture was gradually warmed to room temperature and stirred for 3 hrs. The reaction mixture was quenched with water (150 mL) and extracted with Et.sub.2O (2×100 mL). The combined organic layers were washed with brine and concentrated to give a brown oil, which was purified by column chromatography on silica gel using 100% hexane to yield compound 6a as yellow oil (12.5 g, 89%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 6.99 (s, 1H), 6.70 (s, 1H), 2.77 (t, 2H, J=8 Hz), 1.65 (q, 2H, J=8 Hz), 1.44-1.20 (m, 22H), 0.89 (t, 3H, J=6.8 Hz).

(12) Preparation of Compound 5a

(13) A solution of compound 8a (6.35 g, 13.6 mmol), compound 6a (10.75 g, 30 mmol) and Pd(PPh.sub.3).sub.4 (1.58 g, 1.36 mmol) were mixed in DMF (60 mL) and stirred at 90° C. for 4 hrs. The resultant suspension was diluted with H.sub.2O (100 mL) and the solids were isolated by filtration. The solids were taken up in a hexane/ethyl acetate mixture (v/v 3:1, 60 mL) and the slurry was stirred for 30 minutes at 60° C. The resultant suspension was cooled to room temperature and the solids were collected by filtration, and washed thoroughly with hexane (3×20 mL) to yield compound 5a as yellow solid (6.6 g, 69%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.26 (s, 2H), 6.99 (s, 2H), 6.70 (s, 2H), 2.81 (t, 4H, J=7.6 Hz), 1.70 (m, 4H, J=7.6 Hz), 1.44-1.20 (m, 44H), 0.87 (t, 6H, J=7.6 Hz).

(14) Preparation of Compound 4a

(15) A solution of compound 5a (6.6 g, 9.46 mmol) in CHCl.sub.3 (200 mL) was treated with N-bromo-succinimide (3.7 g, 20.8 mmol) portion wise over 30 minutes at 0° C. The resultant mixture was gradually warmed to room temperature and stirred for 3 hrs. H.sub.2O (300 mL) was added to the reaction mixture and extracted with CH.sub.2Cl.sub.2 (3×60 mL). The combined organic layers were dried and concentrated to give a brown solid. The solid was taken up in a hexane/ethyl acetate mixture (v/v 3:1, 100 mL) and stirred for 30 minutes at 60° C. The resultant solids were collected by filtration and washed thoroughly with hexane (3×10 mL) to yield compound 4a as yellow solid (6.3 g, 77%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.60 (s, 2H), 6.83 (s, 2H), 2.74 (t, 4H, J=7.6 Hz), 1.67 (m, 4H, J=7.6 Hz), 1.44-1.20 (m, 44H), 0.87 (t, 6H, J=6.8 Hz).

(16) Preparation of Compound 3a

(17) Compound 4a (2.56 g, 3 mmol), trimethyl(2-tributylstannylethynyl)silane (3.50 g, 9 mmol) and Pd(PPh.sub.3).sub.4 (350 mg, 0.3 mmol) were mixed in DMF (50 mL) and stirred at 120° C. for 3 hrs. The reaction mixture was diluted with H.sub.2O (150 mL) and extracted with CH.sub.2Cl.sub.2 (3×60 mL). The combined organic layers were dried and concentrated in vacuo to give a brown oil, which was purified by column chromatography on silica gel using 100% hexane to give compound 3a as yellow solid (2 g, 74%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.81 (s, 2H), 6.90 (s, 2H), 2.76 (t, 4H, J=7.6 Hz), 1.63 (m, 4H, J=7.6 Hz), 1.44-1.20 (m, 44H), 0.92 (t, 6H, J=7.2 Hz), 0.30 (s, 18H).

(18) Preparation of Compound 2a

(19) A reaction mixture of compound 3a (1.90 g, 2.15 mmol) and K.sub.2CO.sub.3 (1.13 g, 8.15 mmol) in MeOH/THF (v/v 1:1, 60 mL) mixture was stirred at room temperature for 20 hrs. The resultant suspension was diluted with THF (20 mL) and filtered. The residue was washed thoroughly with CH.sub.2Cl.sub.2 (20 mL) and the filtrate was concentrated in vacuo. The resultant crude solids were purified by column chromatography on silica gel using 100% hexane to yield compound 2a as yellow solid (0.8 g, 50%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.81 (s, 2H), 6.90 (s, 2H), 3.68 (s, 2H), 2.77 (t, 4H, J=7.6 Hz), 1.68 (m, 4H), 1.44-1.20 (m, 44H), 0.87 (t, 6H, J=7.2 Hz).

(20) Preparation of Compound 1a

(21) Compound 2a (100 mg, 0.134 mmol) and PtCl.sub.2 (16 mg, 0.027 mmol) were mixed in toluene (20 mL) and heated at 60° C. for 20 hrs. The reaction mixture was cooled to room temperature and filtered. The filtrate was concentrated and purified by column chromatography on silica gel using hexane/toluene (v/v 3:1) to yield compound 1a as yellow solid (8 mg, 8%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.81 (d, 2H, J=8.4 Hz), 7.76 (d, 2H, J=8.4 Hz), 2.99 (t, 4H, J=7.6 Hz), 1.81 (m, 4H, J=7.6 Hz), 1.45-1.15 (m, 44H), 0.87 (t, 6H, J=6.8 Hz).

Example 2

(22) Preparation of Compound 1 b

(23) ##STR00025##
Preparation of Compound 12a

(24) Commercially available LDA solution (2 M, 10 mL, 20.0 mmol) was diluted in THF (75 mL) solution at 0° C. A solution of compound 7a (6 g, 16.7 mmol) in THF (75 mL) was added drop wise to the dilute LDA solution at 0° C. using a dropping funnel. The resultant mixture was gradually warmed to room temperature and stirred for 3 hrs. The reaction mixture was then cooled to −78° C. and transferred via cannula into a cooled solution of I.sub.2 in THF (150 mL) at −78° C. The reaction mixture was allowed to stir at this temperature for 2 hrs. The reaction mixture was quenched with water (150 mL) and extracted with Et.sub.2O (2×150 mL). The combined organic layers were washed with Na.sub.2S.sub.2O.sub.3, dried over MgSO.sub.4 and concentrated. The crude material was purified by column chromatography on silica gel using 100% hexane to yield compound 12a as yellow oil (7 g, 86%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 6.60 (s, 1H), 2.75 (t, 2H, J=7.2 Hz), 1.62 (m, 2H, J=7.2 Hz), 1.30-1.25 (m, 22H), 0.89 (t, 3H, J=7.2 Hz).

(25) Preparation of Compound 11a

(26) Compound 8a, prepared as described in example 1, (2.3 g, 4.93 mmol), compound 12a (6.7 g, 13.8 mmol) and Pd(PPh.sub.3).sub.4 (0.6 g, 0.49 mmol) were added in a reaction vessel and evacuated 3 times with nitrogen. DMF (49 mL) was then added and stirred at 70° C. for 22 h. The resultant suspension was diluted with H.sub.2O (100 mL) and the solids were isolated by filtration. The solids were washed thoroughly with H.sub.2O (5×50 mL) and hexane (20 mL) to yield compound 11a as orange solid (4 g, 95%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.52 (s, 2H), 6.73 (s, 2H), 2.76 (t, 4H, J=7.6 Hz), 1.67 (m, 4H, J=7.6 Hz), 1.36-1.26 (m, 44H), 0.88 (t, 6H, J=7.6 Hz).

(27) Preparation of Compound 10a

(28) Into a solution of compound 11a in 8 mL anhydrous THF at −78° C., 1.6 M n-BuLi (0.55 mL, 0.88 mmol) was added dropwise within 15 minutes. The solution changed from greenish yellow to slurry orange solution. After 2 hrs stirring at −78° C., DMF (0.1 mL, 1.2 mmol) in 2 mL anhydrous THF was added. The reaction mixture was slowly allowed to warm up to room temperature and stirred overnight. The mixture was poured into 30 mL water and then extracted with diethyl ether (3×20 mL). The organic layer was washed with water (3×20 mL), dried over anhydrous MgSO.sub.4, and concentrated. The orange solid was purified by column chromatography using hexane/toluene (v/v 3:1) to give compound 10a as orange crystalline solid (202 mg, 67%).

(29) .sup.1H NMR (400 MHz, CD.sub.2Cl.sub.2) δ 10.08 (s, 2H), 7.48 (s, 2H), 7.22 (s, 2H), 2.82 (t, 4H, J=8 Hz), 1.71 (m, 4H, J=7.6 Hz), 1.40-1.27 (m, 44H), 0.88 (t, 6H, J=6.8 Hz).

(30) Preparation of Compound 9a

(31) Into a slurry white solution of (methoxymethyl) triphenylphosphonium chloride (1.061 g, 3.1 mmol) and 20 mL anhydrous THF at 0° C., cooled on ice bath, anhydrous potassium tert-butoxide (321 mg, 2.86 mmol) was added, the reaction turned into orange solution immediately and followed by stirring for 1 h at 0° C. The compound 10a (377 mg, 0.5 mmol) was added, the reaction solution was warmed up to room temperature and stirred for 3 hrs. The mixture was washed with water (20 mL), extracted with toluene (3×20 mL). The organic layer was collected, washed with water, dried with anhydrous MgSO.sub.4, and concentrated. The orange residue was purified by column chromatography using hexane/toluene (v/v 9:1) to give compound 9a as orange solid (307 mg, 76%). .sup.1H NMR (400 MHz, CD.sub.2Cl.sub.2) δ 7.21 (s, 2H), 7.03 (d, 2H, J=13.2 Hz), 6.77 (s, 2H), 6.10 (d, 2H, J=13.2 Hz), 3.68 (s, 6H), 2.76 (t, 4H, J=8 Hz), 1.68 (m, 4H, J=7.6 Hz), 1.39-1.27 (m, 44H), 0.88 (t, 6H, J=7.2 Hz).

(32) Preparation of Compound 1b

(33) Into a 50 mL Schlenk flask covered with aluminium foil, compound 9a (81 mg, 0.1 mmol) was dissolved in 2 mL of anhydrous dichloromethane. The solution was cooled on ice. After the addition of 1 drop of methanesulfonic acid, the reaction solution was warmed up to room temperature and stirred overnight. The precipitates were filtered and washed with methanol to yield a yellow solid. The crude compound 1b was recrystallized from hot hexane to yield compound 1b as yellow solid (45 mg, 60%). .sup.1H NMR (400 MHz, CD.sub.2Cl.sub.2) δ 7.80 (d, 2H, J=8.4Hz), 7.74 (d, 2H, J=8.4Hz), 7.16 (s, 2H), 2.98 (t, 4H, J=7.6 Hz), 1.80 (q, 4H, J=7.6 Hz), 1.45-1.21(m, 44H), 0.87 (t, 6H, J=7.2 Hz).

Example 3

(34) Preparation of Bottom-Gate, Top-Contact Organic Field Effect Transistors (OFETs) Comprising Compound 1a, Respectively, 1b as Semiconducting Material

(35) Thermally grown silicon dioxide (thickness: 200 nm) was used as dielectric layer. The gate electrode was formed by depositing highly doped silicon on one side of the dielectric layer. The semiconducting layer was formed by evaporation of compound 1a, respectively, by either evaporation or solution deposition (chlorobenzene, 1 mg/ml, drop casting at 70° C.) of compound 1b on the other side of the dielectric layer. Source/drain Au electrodes (thickness: 50 nm) were deposited through a shadow mask to give top-contact OFET devices. The channel width (W) was typically 50 μm and channel length (L) is 1000 μm.

(36) The design of the bottom-gate, top-contact organic field effect transistor of example 3 is shown in FIG. 1.

Example 4

(37) Measurement of the Transfer Curves and the Output Curves of the Bottom-Gate, Top-Contact Organic Field Effect Transistors (OFETs) Comprising Compound 1a, Respectively, 1b

(38) The drain current I.sub.d [A] in relation to the gate-source voltage V.sub.g [V] (top transfer curve) and the drain current I.sub.d.sup.1/2 [A.sup.1/2] in relation to the gate-source voltage V.sub.g [V] (bottom transfer curve) for the bottom-gate top-contact organic field effect transistor of example 3 comprising compound 1b as semiconducting material at a drain voltage V.sub.d of −60 V was determined in air at room temperature using a Keithley 4200 machine. The results are shown in FIG. 2.

(39) The drain current I.sub.d [A] in relation to the drain voltage V.sub.d [V] (output curves) for the bottom-gate, top-contact organic field effect transistor of example 3 comprising compound 1b as semiconducting material at a gate-source voltage V.sub.g of −60 V (first and top curve), −40 V (second curve), −20 V (third curve) and 0 V (fourth and bottom curve) was determined in air at ambient temperature using a Keithley 4200 machine. The results are shown in FIG. 3.

(40) The drain current I.sub.d [A] in relation to the gate-source voltage V.sub.g [V] (top transfer curve) and the drain current I.sub.d.sup.1/2 [10.sup.−3 A.sup.1/2] in relation to the gate-source voltage V.sub.g [V] (bottom transfer curve) for the bottom-gate top-contact organic field effect transistor of example 3 comprising compound 1a as semiconducting material at a drain voltage V.sub.d of −40 V was determined in air at room temperature using a Keithley 4200 machine. The results are shown in FIG. 4.

(41) The drain current I.sub.d [μA] in relation to the drain voltage V.sub.d [V] (output curves) for the bottom-gate, top-contact organic field effect transistor of example 3 comprising compound 1a as semiconducting material at a gate-source voltage V.sub.g of −60 V (first and top curve), −55 V (second curve), −50 V (third curve) and −45 V (fourth and bottom curve) was determined in air at ambient temperature using a Keithley 4200 machine. The results are shown in FIG. 5.

(42) The compounds 1a and 1b show the typical behavior of a p-type semiconducting material.

(43) The charge-carrier mobility was extracted in the saturation regime from the slope of I.sub.d.sup.1/2 [μA.sup.1/2] versus V.sub.g [V]. The threshold voltage V.sub.th [V] was obtained using the following equation:
μ=2I.sub.d/{(W/L)C.sub.μ(V.sub.g−V.sub.th).sup.2}
wherein Cμ is the capacitance of the dielectric layer.

(44) The average values of the charge carrier mobility μ.sub.sat [cm.sup.2/V s], the I.sub.ON/I.sub.OFF ratio and the threshold voltage V.sub.th [V] for the bottom-gate, top-contact organic field effect transistor of example 3 comprising compound 1a, respectively, 1b as semiconducting material are given in table 1.

(45) TABLE-US-00001 TABLE 1 process of deposition of μ.sub.sat V.sub.th Compounds semiconducting layer [cm.sup.2/V s] I.sub.on/I.sub.off [V] 1a Evaporation 0.90 3 * 10.sup.8 −47 1b Solution 8 * 10.sup.−3 5 * 10.sup.3 −39 1b Evaporation 0.03 1 * 10.sup.5 −47

Example 5

(46) Preparation of Compound 1a

(47) ##STR00026##
Preparation of Compound 12a

(48) A solution of 5a (7.8 g, 11.2 mmol), prepared as described in example 1, in CH.sub.2Cl.sub.2 (100 ml) was added drop wise to a mixture of POCl.sub.3 and DMF in CH.sub.2Cl.sub.2 over 30 minutes at 0° C. The resultant mixture was gradually warmed to room temperature and stirred in a 40° C. hot water bath for 2 hours. The reaction mixture was diluted with CH.sub.2Cl.sub.2 and poured into ice (250 g) and stirred. KOAc (25 g) was added portion wise into the cold solution and mixed thoroughly. The organic layer was separated and concentrated to give crude product. The resultant solids were collected by filtration and washed thoroughly with CH.sub.2Cl.sub.2 (3×20 mL) to yield yellow solid (9.0 g, 98%).

(49) .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.60 (s, 2H), 6.83 (s, 2H), 2.74 (t, 4H, J=7.6 Hz), 1.67 (q, 4H, J=7.6 Hz), 1.44-1.20 (m, 44H), 0.87 (t, 6H, J=6.8 Hz).

(50) Preparation of Compound 13a

(51) 12a (2.4 g, 3.0 mmol) in THF (90 mL) was added drop wise to a mixture of (methoxymethyl)triphenylphosphonium chloride (6.2 g, 18 mmol) and KO.sup.tBu (2.0 g, 18 mmol) in THF (60 ml) at −50° C. in a dry ice-acetonitrile bath. The resultant mixture was left to stir in the cooling bath and slowly warmed to room temperature over 16 hrs. The reaction mixture was diluted with diethyl ether (100 mL) and brine (100 mL). The organic layer was separated and the aqueous layer further extracted with CH.sub.2Cl.sub.2 (3×50 mL). Combined organic layers were concentrated and purified by column chromatography on silica gel using hexanes/toluene (v/v 1:1) to give yellow solid (1.1 g, 42%). .sup.1H NMR (400 MHz, CDCl.sub.3) δ 7.21 (s, 2H), 6.96 (d, 2H, J=12.8 Hz), 6.79 (s, 2H), 6.24 (d, 2H, J=12.8 Hz), 3.69 (s, 2H), 2.77-2.70 (m, 4H), 1.62-1.75 (m, 4H), 1.45-1.20 (m, 44H), 0.87 (t, 6H, J=6.8 Hz).

(52) Preparation of Compound 1a

(53) An isomeric mixture of 13a in CH.sub.2Cl.sub.2 (45 mL) was treated with methanesulfonic acid (0.05 mL) drop wise at 0° C. in the dark. The resultant mixture and stirred for 16 hrs at room temperature. The reaction mixture was concentrated to dryness and the resultant precipitate triturated with methylene chloride, then separated by filtration. The residue was washed with H.sub.2O and methanol. The crude product was recrystallized from hot hexanes to give yellow solid (0.5 g, 52%).

(54) .sup.1H NMR (400 MHz, CD.sub.2Cl.sub.2) δ 7.84 (d, 2H, J=8.4 Hz), 7.77 (d, 2H, J=8.4 Hz), 7.27 (s, 2H), 2.98 (t, 4H, J=7.6 Hz), 1.75-1.85 (m, 4H), 1.40-1.20 (m, 44H), 0.85 (t, 6H, J=6.8 Hz).