BISPYRANILIDENES, DITHIOBISPYRANILIDENES AND DISELENOBISPYRANILIDENE AND USE THEREOF

Abstract

The invention relates to bispyranilidenes, dithiobispyranilidenes and diselenobispyranilidene according to formula (I), to the use thereof as light or IR-absorber and to an electronic or optoelectronic component containing at least one compound according to formula (I).

##STR00001##

Claims

1. A compound according to formula (I) ##STR00027## wherein X.sup.1 and X.sup.2 are each independently selected from the group consisting of oxygen, sulfur and selenium, R.sup.1 and R.sup.2 are each independently selected from the group consisting of substituted thiophene and selenophene residues.

2. The compound according to claim 1, wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of ##STR00028## wherein R.sup.3 is selected from C1 to C20 alkyl and cycloalkyl residues, C1 to C20 perfluoroalkyl residues, C1 to C20 aryl and heteroaryl residues, C1 to C20 alkoxy and thiaalkoxy residues, and primary, secondary and tertiary C1 to C20 alkylamino residues.

3. The compound according to claim 1, wherein R.sup.3 is selected from the group including methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, iso-pentafluoropropyl, nonafluorobutyl, tert-nonafluorobutyl, iso-nonafluorobutyl, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoropropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-nonafluoropentyl, 2,2,3,4,4,5,5,6,6-unododecafluorohexyl, phenyl, benzyl, diphenyl, naphthyl, anthryl, phenanthryl, pyridyl, furanyl, thienyl, thiazyl, oxazyl, imidazyl, pyrimidyl, thiazinyl, methoxy, ethoxy, propoxy, butoxy, pentoxy, thiomethoxy, thioethoxy, thiopropoxy, iso-thiopropoxy, thiobutoxy, iso-thiobutoxy, tert-thiobutoxy, thiohexoxy, iso-thiohexoxy, amino, methylamino, butylamino, tolylamino, dimethylamino, diethylamino, methylphenylamino, methyltolylamino, pyrrolidine, piperidine, morpholine, thiomorpholine and ditolylamine.

4. The compound according to claim 1, wherein R.sup.1 and R.sup.2 are identical.

5. The compound according to claim 1, wherein X.sup.1 and X.sup.2 are each independently selected from the group consisting of sulfur and selenium.

6. The compound according to claim 1, wherein X.sup.1 and X.sup.2 are identical.

7. The compound according to claim 1, wherein X.sup.1 and X.sup.2 are oxygen and sulfur, oxygen and selenium, or sulfur and selenium.

8. (canceled)

9. An electronic or optoelectronic component comprising the compound according to claim 1.

10. The electronic or optoelectronic component according to claim 9, wherein said electronic or optoelectronic component is selected from: an organic solar cell (OSC) donor absorber material; a hole transport material (HTM) in dye-sensitized solar cells (DSSC, Grätzel cells); an organic integrated circuit (O-IC); an organic field-effect transistor (OFET); an organic thin-film transistor (O-TFT); an organic light emitting diodes (OLED); a photodetector; and an IR sensor.

11. The electronic or optoelectronic component according to claim 9, wherein said electronic or optoelectronic component is an infrared (IR) charge transfer (CT) absorption sensors.

12. The compound according to claim 2, wherein R.sup.3 is selected from the group including methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, iso-pentafluoropropyl, nonafluorobutyl, tert-nonafluorobutyl, iso-nonafluorobutyl, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoropropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-nonafluoropentyl, 2,2,3,4,4,5,5,6,6-unododecafluorohexyl, phenyl, benzyl, diphenyl, naphthyl, anthryl, phenanthryl, pyridyl, furanyl, thienyl, thiazyl, oxazyl, imidazyl, pyrimidyl, thiazinyl, methoxy, ethoxy, propoxy, butoxy, pentoxy, thiomethoxy, thioethoxy, thiopropoxy, iso-thiopropoxy, thiobutoxy, iso-thiobutoxy, tert-thiobutoxy, thiohexoxy, iso-thiohexoxy, amino, methylamino, butylamino, tolylamino, dimethylamino, diethylamino, methylphenylamino, methyltolylamino, pyrrolidine, piperidine, morpholine, thiomorpholine and ditolylamine.

13. The compound according to claim 2, wherein R.sup.1 and R.sup.2 are identical.

14. The compound according to claim 3, wherein R.sup.1 and R.sup.2 are identical.

15. The compound according to claim 2, wherein X.sup.1 and X.sup.2 are each independently selected from the group consisting of sulfur and selenium.

16. The compound according to claim 3, wherein X.sup.1 and X.sup.2 are each independently selected from the group consisting of sulfur and selenium.

17. The compound according to claim 2, wherein X.sup.1 and X.sup.2 are identical.

18. The compound according to claim 3, wherein X.sup.1 and X.sup.2 are identical.

19. The compound according to claim 2, wherein X.sup.1 and X.sup.2 are oxygen and sulfur, oxygen and selenium, or sulfur and selenium.

20. The compound according to claim 3, wherein X.sup.1 and X.sup.2 are oxygen and sulfur, oxygen and selenium, or sulfur and selenium.

21. The compound according to claim 12, wherein R.sup.1 and R.sup.2 are identical, and X.sup.1 and X.sup.2 are identical and are selected from the group consisting of sulfur and selenium; or X.sup.1 and X.sup.2 are oxygen and sulfur, oxygen and selenium, or sulfur and selenium.

Description

[0099] It is shown in

[0100] FIG. 1 the UV-Vis absorption spectra of thienyl-substituted bispyranylidene and dithiobispyranilidene in dimethylformamide (DMF) (c=10.sup.−5 mol/l);

[0101] FIG. 2 the measurement of the external quantum efficiency (EQE) and internal quantum efficiency (IQE) of optoelectronic devices comprising 2,2′,6,6′-tetrathienyl-4,4′-dithiobispyranylidene (reference) (circles) or 2,2′,6,6′-tetra(2-methylthienyl)-4,4′-dithiobispyranylidene (squares) and C60. Unfilled characters represent the IQE in the spectral range from 425 nm to 525 nm (IQE=EQE.Math.absorbance.sup.−1), the dashed line represents the average IQE, filled characters represent the EQE;

[0102] FIG. 3 a) the CT absorption profiles σ.sub.CT of the mixtures of the compounds with C60 (linear and logarithmic scaling); b) oscillator strength f.sub.σ; c) structure of the symmetric thienyl-substituted bispyranylidenes and dithiobispyranilidenes.

GENERAL SYNTHESIS WORKING TECHNIQUES

[0103] Solvents are cleaned and dried before use according to standard techniques.

Electron Spray Ionization Mass Spectrometry, ESI-MS

[0104] Mass spectrometry is performed using Bruker Esquire Ion Trap (ESI/APCI) and a sample concentration of 2 mg/I.

Nuclear Magnetic Resonance (NMR) Spectroscopy

[0105] NMR spectra are measured using either a Bruker AC 300, AC 600 or a Bruker DRX 500 nuclear magnetic resonance spectrometer in deuterated solvents at 26 to 30° C. Shifts of the 1H and 13C resonances are given in ppm relative to the residual signal of the non-deuterated solvent. Coupling constants are given in Hz without indication of sign, using the following abbreviations for the multiplicities of the individual signals: s: Singlet; d: doublet; dd: doublet of doublets; t: triplet; qua: quartet; qi: quintet; sep: septet; m: multiplet; br.s.: broad signal.

Ultraviolet-Visible (UV-Vis) Absorption Spectroscopy

[0106] Optical characterization is performed using UV-Vis spectroscopy to determine the optical bandwidth, the shape of the absorption band and the extinction coefficient. UV-Vis spectra are measured using a Perkin Elmer Lambda 25 UV/VIS spectrophotometer with a scan rate of 600 nm/min.

Synthesis Recipe for 1,5-di-(2-thienyl)pentane-1,5-dione

[0107] 15 ml of anhydrous dichloromethane (DCM) is added to 16.0 g (120 mmol, 2 eq.) of aluminum chloride in a 100 ml round-bottom flask under an inert gas atmosphere. Dropwise, a solution of 11.6 ml (120 mmol, 2.4 eq.) thiophene and 6.4 ml (50 mmol, 1 eq.) glutaryl chloride in 15 ml DCM is added over 10 min. Upon addition, the color changes from light orange to dark red. The solution is stirred overnight, and the flask is cooled in an ice bath. The reaction is stopped using ice and concentrated hydrochloric acid (2 ml). Water is added while stirring until the exothermic reaction with the excess aluminum chloride is completed. The mixture is diluted with 50 ml of DCM and stirred for 2 h. The organic phase is extracted with warm DCM, dried over magnesium sulfate and concentrated under vacuum. The crude product is ground and washed with cold diethyl ether.

##STR00006##

[0108] Molecular formula: C.sub.13H.sub.12O.sub.2S.sub.2 (264.03 g/mol)

[0109] Yield: 11.2 g (42.3 mmol, 85%)

[0110] ESI-MS: m/z 265 [M].sup.+

[0111] .sup.1H-NMR (500 MHz, CDCl.sub.3, ppm): δ=7.73 (dd, J=3.8, 1.1 Hz, 1H), 7.61 (dd, J=4.9, 1.1 Hz, 1H), 7.10 (dd, J=4.9, 3.8 Hz, 1H), 3.04 (t, J=7.0 Hz, 2H), 2.19 (qt, J=7.0, 3.5 Hz, 1H).

[0112] .sup.13C-NMR (75 MHz, CDCl.sub.3, ppm): δ=193.39, 144.81, 134.22, 132.68, 128.78, 38.81, 19.96.

Synthesis Recipe for 2,6-di-(2-thienyl)pyrylium tetrafluoroborate

[0113] 9.7 ml (76.2 mmol, 10 eq.) tetrafluoroboric acid solution (50% (m/m) in water) is added dropwise over 30 min to a suspension of 2.0 g (7.6 mmol, 1 eq.) 1,5-di-(2-thienyl)pentane-1,5-dione in 50 ml acetic anhydride while maintaining the temperature below 15° C. using an ice bath. After the addition is complete, the mixture is stirred for another 2 h at room temperature and left overnight at 5° C. After the addition of 500 ml of hexane/diethyl ether (1:10), a brown precipitate precipitates. The product is obtained by vacuum filtration, washing with diethyl ether and vacuum drying at room temperature.

##STR00007##

[0114] Molecular formula: C.sub.13H.sub.9BF.sub.4OS.sub.2 (332.01 g/mol)

[0115] Yield: 1.59 g (4.8 mmol, 63%)

[0116] ESI-MS: m/z 245 [M-BF.sub.4]+, 277 [M-BF.sub.4+CH.sub.3OH].sup.+

[0117] Absorption (DCM): α.sub.max=489 nm (ε=30458 Lmol.sup.−1cm.sup.−1)

[0118] .sup.1H-NMR (500 MHz, acetonitrile, ppm): δ=8.61 (t, J=8.4 Hz, 1H), 8.28 (dd, J=4.0, 1.1 Hz, 2H), 8.21 (dd, J=4.9, 1.1 Hz, 2H), 8.08 (d, J=8.4 Hz, 2H), 7.44 (dd, J=4.9, 4.1 Hz, 2H).

[0119] .sup.13C-NMR (75 MHz, acetonitrile, ppm): δ=167.00, 155.90, 140.54, 186.98, 188.28, 181.95, 117.71.

Synthesis Recipe for 2,2′,6,6′-tetrathienyl-4,4′-bispyranylidene

[0120] Under an inert gas atmosphere, 1.2 ml (4.7 mmol, 1 eq.) of tributyl phosphine is added to an orange suspension of 1.56 g (4.7 mmol, 1 eq.) of 2,6-di-(2-thienyl)pyrylium tetrafluoroborate in 50 ml of dried acetonitrile. The mixture changes color to yellow and is stirred for 2.5 h at room temperature. Then 4.0 ml (23.5 mmol, 5 eq.) of N,N-diisopropylethylamine is added. The mixture is refluxed at 95° C. for 2 h under an inert gas atmosphere and allowed to stand overnight. The product is obtained as a black solid after filtration, washing with acetonitrile and drying in air.

##STR00008##

[0121] Molecular formula: C.sub.26H.sub.16O.sub.2S.sub.4 (488.00 g/mol)

[0122] Yield: 0.62 g (1.27 mmol, 54%)

[0123] ESI-MS: m/z 488 [M].sup.+

[0124] Absorption (DMF): α.sub.max=482 nm (c=29610 Lmol.sup.−1 cm.sup.−1)

[0125] Melting point: 239° C.

[0126] .sup.1H-NMR (500 MHz, CDCl.sub.3, ppm): δ=7.74 (dd, J=3.7, 1.1 Hz, 1H), 7.65 (dd, J=5.0, 1.1 Hz, 1H), 7.21 (dd, J=5.0, 3.7 Hz, 1H), 6.95 (s, 1H).

[0127] .sup.13C-NMR (125.75 MHz, CDCl.sub.3, ppm): δ=144.90, 136.50, 12.08, 126.42, 124.15, 113.68, 101.85.

Synthesis Recipe for 2,6-dithienylthiopyrylium perchlorate

[0128] 7.80 g (29.5 mmol, 1.0 eq.) 1,5-di-(2-thienyl)pentane-1,5-dione, 9.86 g (44.3 mmol, 1.5 eq.) phosphorus(V) sulfide, 180 ml acetic acid, and 18.90 g (60 mmol, 6.0 eq.) lithium perchlorate are successively introduced into a 250 ml round-bottom flask. The mixture is boiled for 3 h under reflux. The color changes from orange to dark red. A green solid is obtained by filtration and washing with hot acetic acid. The filtrate is concentrated under vacuum and a black solid is obtained by adding an excess of diethyl ether and storing at 5° C. overnight. The crude product is recrystallized in acetic acid to obtain green crystals.

##STR00009##

[0129] Molecular formula: C.sub.13H.sub.9ClO.sub.4S.sub.3 (359.94 g/mol)

[0130] Yield: 3.0 g (8.3 mmol, 28%)

[0131] ESI-MS: m/z 261 [M-ClO.sub.4].sup.+

[0132] Absorption (DCM): α.sub.max=514 nm (c=31902 Lmol.sup.−1cm.sup.−1)

[0133] .sup.1H-NMR (500 MHz, Acetonitril, ppm): δ=8.55 (t, J=8.8 Hz, 1H), 8.43 (d, J=8.7 Hz, 2H), 8.20-8.04 (m, 4H), 7.42 (dd, J=4.9, 4.0 Hz, 2H).

[0134] .sup.13C-NMR (125.75 MHz, Acetonitril, ppm): δ=162.24, 151.35, 139.07, 137.80, 134.81, 132.50, 130.26.

Synthesis Recipe for 2,2′,6,6′-tetrathienyl-4,4′-dithiobispyranylidene (Reference)

[0135] Under an inert gas atmosphere, 0.65 ml (2.6 mmol, 1 eq.) of tributyl phosphine is added to a violet suspension of 0.95 g (2.6 mmol, 1 eq.) of 2,6-dithienylthiopyrylium perchlorate in 50 ml of dried acetonitrile. The mixture changes color to gray and is stirred for 2.5 h at room temperature. Then 2.2 ml (13.0 mmol, 5 eq.) of N,N-diisopropylethylamine is added. The mixture is boiled under reflux at 95° C. for 2 h under an inert gas atmosphere and allowed to stand overnight. The product is obtained as a black solid after filtration and recrystallization from DMSO.

##STR00010##

[0136] Molecular formula: C.sub.26H.sub.16S.sub.6 (519.96 g/mol)

[0137] Yield: 0.26 g (0.5 mmol, 39%)

[0138] ESI-MS: m/z 520 [M].sup.+

[0139] Absorption (DMF): α.sub.max=512 nm

[0140] Melting point: 314° C.

[0141] .sup.1H-NMR (500 MHz, pyridine, ppm): δ=7.52 (dd, J=5.1, 1.1 Hz, 1H), 7.50 1 7.46 (m, 1H), 7.40 (s, 1H), 7.13 (dd, J=5.1, 3.7 Hz, 1H).

Synthesis Recipe for 1,5-di-(2-(5-methyl)thienyl)pentane-1,5-dione

[0142] 15 ml of anhydrous dichloromethane (DCM) is added to 16.0 g (120 mmol, 2 eq.) of aluminum chloride in a 100 ml round-bottom flask under an inert gas atmosphere. Dropwise, a solution of 11.6 ml (120 mmol, 2.4 eq.) 2-methylthiophene and 6.4 ml (50 mmol, 1 eq.) glutaryl chloride in 15 ml DCM is added over 10 min. Upon addition, the color changes from light orange to dark red. The solution is stirred overnight, and the flask is cooled in an ice bath. The reaction is stopped using ice and concentrated hydrochloric acid (2 ml). Water is added while stirring until the exothermic reaction with the excess aluminum chloride is completed. The mixture is diluted with 50 ml of DCM and stirred for 2 h. The organic phase is removed. The organic phase is extracted with warm DCM, dried over magnesium sulfate, and concentrated under vacuum. The crude product is ground and washed with cold diethyl ether.

##STR00011##

[0143] Molecular formula: C.sub.15H.sub.16O.sub.2S.sub.2 (292.06 g/mol)

[0144] Yield: 9.9 g (33.8 mmol, 68%)

[0145] ESI-MS: m/z 293 [M].sup.+

[0146] .sup.1H-NMR (500 MHz, CDCl.sub.3, ppm): δ=7.53 (d, J=3.7 Hz, 1H), 6.76 (m, 1H), 2.94 (t, J=7.0 Hz, 2H), 2.51 (d, J=0.7 Hz, 3H), 2.13 (p, J=7.0 Hz, 1H).

[0147] .sup.13C-NMR (125.75 MHz, CDCl.sub.3, ppm): δ=192.47, 149.60, 141.96, 132.64, 126.74, 37.75, 19.72, 15.60.

Synthesis Recipe for 2,6-di-(2-(5-methyl)thienyl)pyrylium tetrafluoroborate

[0148] 9.7 ml (76.2 mmol, 10 eq.) tetrafluoroboric acid solution (50% (m/m) in water) is added dropwise over 30 min to a suspension of 2.2 g (7.6 mmol, 1 eq.) 1,5-di-(2-(5-methyl)thienyl)pentane-1,5-dione in 50 ml acetic anhydride while the temperature is maintained below 15° C. using an ice bath. After the addition is complete, the mixture is stirred for another 2 h at room temperature and left overnight at 5° C. After the addition of 500 ml of hexane/diethyl ether (1:10), a red precipitate precipitates. The product is obtained by vacuum filtration, washing with diethyl ether, and vacuum drying at room temperature.

##STR00012##

[0149] Molecular formula: C.sub.15H.sub.13BF.sub.4OS.sub.2 (360.04 g/mol)

[0150] Yield: 1.0 g (2.8 mmol, 37%)

[0151] ESI-MS: m/z 273 [M-BF.sub.4].sup.+, 305 [M-BF.sub.4+CH.sub.3OH].sup.+

[0152] Absorption (DCM): α.sub.max=520 nm (ε=27691 Lmol.sup.−1cm.sup.−1)

[0153] .sup.1H-NMR (500 MHz, Acetonitril, ppm): δ=8.45 (t, J=8.4 Hz, 1H), 8.06 (d, J=4.0 Hz, 2H), 7.88 (d, J=8.4 Hz, 2H), 7.13 (dd, J=4.0, 0.9 Hz, 2H), 2.66 (s, 6H).

[0154] .sup.13C-NMR (75 MHz, acetonitrile, ppm): δ=166.03, 157.53, 154.45, 137.45, 131.13, 130.83, 116.23, 16.58.

Synthesis Recipe for 2,2′,6,6′-tetra-(2-methylthienyl)-4,4′-bispyranylidene

[0155] Under an inert gas atmosphere, 1.2 ml (4.7 mmol, 1 eq.) of tributylphosphine is added to an orange suspension of 1.69 g (4.7 mmol, 1 eq.) of 2,6-di-(2-(5-methyl)thienyl)pyrylium tetrafluoroborate in 50 ml of dried acetonitrile. The mixture changes color to yellow and is stirred for 2.5 h at room temperature. Then 4.0 ml (23.5 mmol, 5 eq.) of N,N-diisopropylethylamine is added. The mixture is boiled under reflux at 95° C. for 2 h under an inert gas atmosphere and allowed to stand overnight. The product is obtained as a black solid after filtration, washing with acetonitrile and drying in air.

##STR00013##

[0156] Molecular formula: C.sub.30H.sub.24O.sub.2S.sub.4 (544.07 g/mol)

[0157] Yield: 0.89 g (1.64 mmol, 70%)

[0158] HR-EI-MS: m/z 544.0661 [M].sup.+

[0159] Absorption (DMF): α.sub.max=488 nm (ε=44663 Lmol.sup.−1cm.sup.−1)

[0160] Melting point: 328° C.

[0161] .sup.1H-NMR (600 MHz, Benzol, ppm): δ=7.16 (s, 1H), 6.45 (d, J=3.0 Hz, 1H), 6.40 (br.s., 1H), 2.11 (br.s., 3H).

Synthesis Recipe for 2,6-di(5-methylthienyl)thiopyrylium perchlorate

[0162] 5.00 g (17.1 mmol, 1.0 eq.) 1,5-di-(2-(5-methyl)thienyl)pentane-1,5-dione, 5.72 g (25.7 mmol, 1.5 eq.) phosphorus (V) sulfide, 250 ml acetic acid, and 10.90 g (102.2 mmol, 6.0 eq.) lithium perchlorate are successively introduced into a 250 ml round-bottom flask. The mixture is boiled for 3 h under reflux. The color changes from orange to deep purple. The mixture is hot filtered and allowed to stand for 48 h. The mixture is refluxed. The green crystals are washed with diethyl ether and dried in air.

##STR00014##

[0163] Molecular formula: C.sub.15H.sub.13ClO.sub.4S.sub.3 (387.97 g/mol)

[0164] Yield: 2.16 g (5.6 mmol, 33%)

[0165] ESI-MS: m/z 289 [M-ClO.sub.4].sup.+

[0166] Absorption (DCM): α.sub.max=552 nm (c=37946 Lmol.sup.−1cm.sup.−1)

[0167] .sup.1H-NMR (500 MHz, acetonitrile, ppm): δ=3.33 (dd, J=9.5, 3.1 Hz, 1H), 3.25 4 3.15 (m, 2H), 7.93 (d, J=4.0 Hz, 2H), 7.13 (dd, J=4.0, 1.0 Hz, 2H), 2.65 (s, 6H).

[0168] .sup.13C-NMR (75 MHz, acetonitrile, ppm): δ=161.09, 156.02, 150.44, 135.56, 135.27, 131.57, 123.49, 16.76.

Synthesis recipe for 2,2′,6,6′-tetra(2-methylthienyl)-4,4′-dithiobispyranylidene

[0169] Under an inert gas atmosphere, 0.7 ml (2.8 mmol, 1 eq.) of tributyl phosphine is added to a violet suspension of 1.10 g (2.8 mmol, 1 eq.) of 2,6-di(5-methylthienyl)thiopyrylium perchlorate in 50 ml of dried acetonitrile. The mixture changes color to gray and is stirred for 2.5 h at room temperature. Then 2.4 ml (14.0 mmol, 5 eq.) of N,N-diisopropylethylamine is added. The mixture is boiled under reflux at 95° C. for 2 h under an inert gas atmosphere and allowed to stand overnight. The product is obtained as a black solid after filtration and recrystallization from DMSO.

##STR00015##

[0170] Molecular formula: C.sub.30H.sub.24S.sub.6 (576.02 g/mol)

[0171] Yield: 0.58 g (1.0 mmol, 72%)

[0172] ESI-MS: m/z 576 [M].sup.+

[0173] Absorption (DMF): α.sub.max=521 nm

[0174] Melting point: 304° C.

[0175] .sup.1H-NMR (500 MHz, pyridine, ppm): δ=7.35 (m, 1H), 7.29 (d, J=3.6 Hz, 1H), 6.76 (dd, J=3.6, 1.1 Hz, 1H), 2.33 (s, 3H).

Synthesis recipe for 1,5-di-(2-(5-ethyl)thienyl)pentane-1,5-dione

[0176] 15 ml of anhydrous dichloromethane (DCM) is added to 16.0 g (120 mmol, 2 eq.) of aluminum chloride in a 100 ml round-bottom flask under an inert gas atmosphere. Dropwise, a solution of 12.7 ml (120 mmol, 2.4 eq.) 2-ethylthiophene and 6.4 ml (50 mmol, 1 eq.) glutaryl chloride in 15 ml DCM is added over 10 min. Upon addition, the color changes from light orange to dark red. The solution is stirred overnight, and the flask is cooled in an ice bath. The reaction is stopped using ice and concentrated hydrochloric acid (2 ml). Water is added while stirring until the exothermic reaction with the excess aluminum chloride is completed. The mixture is diluted with 50 ml of DCM and stirred for 2 h. The organic phase is removed. The organic phase is extracted with warm DCM, dried over magnesium sulfate, and concentrated under vacuum. The crude product is ground and recrystallized from diethyl ether.

##STR00016##

[0177] Molecular formula: C.sub.17H.sub.20O.sub.2S.sub.2 (320.09 g/mol)

[0178] Yield: 10.3 g (32.1 mmol, 64%)

[0179] ESI-MS: m/z 321 [M].sup.+

[0180] .sup.1H-NMR (500 MHz, CDCl.sub.3, ppm): δ=7.55 (d, J=3.8 Hz, 1H), 6.79 (dt, J=3.8, 0.9 Hz, 1H), 2.95 (t, J=7.0 Hz, 2H), 2.85 (qd, J=7.5, 0.6 Hz, 2H), 2.14 (p, J=7.0 Hz, 1H), 1.30 (t, J=7.5 Hz, 3H).

[0181] .sup.13C-NMR (75 MHz, CDCl.sub.3, ppm): δ=192.52, 157.16, 141.46, 132.47, 124.90, 37.76, 24.00, 19.74, 15.53.

Synthesis Recipe for 2,6-di-(2-(5-ethyl)thienyl)pyrylium tetrafluoroborate

[0182] 9.7 ml (76.2 mmol, 10 eq.) tetrafluoroboric acid solution (50% (m/m) in water) is added dropwise over 30 min to a suspension of 2.4 g (7.6 mmol, 1 eq.) 1,5-di-(2-(5-ethyl)thienyl)pentane-1,5-dione in 50 ml acetic anhydride while the temperature is maintained below 15° C. using an ice bath. After the addition is complete, the mixture is stirred for another 2 h at room temperature and left overnight at 5° C. After the addition of 500 ml of hexane/diethyl ether (1:10), a red precipitate precipitates. The product is obtained by vacuum filtration, washing with diethyl ether and vacuum drying at room temperature.

##STR00017##

[0183] Molecular formula: C.sub.17H.sub.17BF.sub.4OS.sub.2 (388.07 g/mol)

[0184] Yield: 1.4 g (3.6 mmol, 48%)

[0185] ESI-MS: m/z 301 [M-BF.sub.4].sup.+

[0186] Absorption (DCM): α.sub.max=524 nm (c=31596 Lmol.sup.−1cm.sup.−1)

[0187] .sup.1H-NMR (500 MHz, Acetonitril, ppm): δ=8.45 (t, J=8.4 Hz, 1H), 8.11 (d, J=4.1 Hz, 2H), 7.89 (d, J=8.4 Hz, 2H), 7.20 (dt, J=4.1, 0.9 Hz, 2H), 3.05 (q, J=7.5 Hz, 4H), 1.39 (t, J=7.5 Hz, 6H).

[0188] .sup.13C-NMR (75 MHz, Acetonitril, ppm): δ=165.95, 164.53, 154.10, 137.05, 130.22, 129.13, 115.99, 24.79, 15.56.

Synthesis Recipe for 2,2′,6,6′-tetra-(2-ethylthienyl)-4,4′-bispyranylidene

[0189] Under an inert gas atmosphere, 1.3 ml (5.2 mmol, 1 eq.) tributylphosphine is added to an orange suspension of 2.0 g (5.2 mmol, 1 eq.) 2,6-di-(2-(5-ethyl)thienyl)pyrylium tetrafluoroborate in 60 ml dried acetonitrile. The mixture changes color to yellow and is stirred for 2.5 h at room temperature. Then 4.4 ml (26 mmol, 5 eq.) of N,N-diisopropylethylamine is added. The mixture is boiled under reflux at 95° C. for 2 h under an inert gas atmosphere and allowed to stand overnight. The product is obtained as a black solid after filtration, washing with acetonitrile and drying in air.

##STR00018##

[0190] Molecular formula: C.sub.34H.sub.32O.sub.2S.sub.4 (600.13 g/mol)

[0191] Yield: 1.0 g (1.67 mmol, 64%)

[0192] HR-EI-MS: m/z 600.1288 [M].sup.+

[0193] Absorption (DMF): α.sub.max=488 nm (c=51749 Lmol.sup.−1 cm.sup.−1)

[0194] Melting point: 221° C.

[0195] .sup.1H-NMR (500 MHz, benzene, ppm): δ=7.16 (s, 1H), 6.52 (d, J=3.5 Hz, 1H), 6.44 (br.s., 1H), 2.53 (br.s., 2H), 1.07 (t, J=7.6 HZ, 3H).

Synthesis recipe for 2,6-di(5-ethylthienyl)thiopyrylium perchlorate

[0196] 4.00 g (12.6 mmol, 1.0 eq.) 1,5-di-(2-(5-ethyl)thienyl)pentane-1,5-dione, 4.21 g (18.9 mmol, 1.5 eq.) phosphorus (V) sulfide, 250 ml acetic acid, and 8.07 g (75.6 mmol, 6.0 eq.) lithium perchlorate are successively introduced into a 250 ml round-bottom flask. The mixture is boiled for 3 h under reflux. The color changes from orange to deep purple. The mixture is hot filtered and allowed to stand for 48 h. The mixture is refluxed. The green crystals are washed with diethyl ether and dried in air.

##STR00019##

[0197] Molecular formula: C.sub.17H.sub.17ClO.sub.4S.sub.3 (416.00 g/mol)

[0198] Yield: 2.23 g (5.4 mmol, 43%)

[0199] ESI-MS: m/z 317 [M-C104].sup.+

[0200] Absorption (DCM): α.sub.max=554 nm (c=39270 Lmol.sup.−1 cm.sup.−1)

[0201] .sup.1H-NMR (300 MHz, Acetonitril, ppm): δ=8.39 (dd, J=9.6, 3.0 Hz, 1H), 8.26-8.16 (m, 2H), 7.95 (d, J=4.0 Hz, 2H), 7.18 (dt, J=4.0, 0.9 Hz, 2H), 3.01 (q, J=7.5 Hz, 4H), 1.37 (t, J=7.5 Hz, 6H).

[0202] .sup.13C-NMR (125.75 MHz, CDCl.sub.3, ppm): δ=161.92, 159.34, 149.72, 134.38, 133.70, 128.64, 126.94, 24.42, 15.28.

Synthesis Recipe for 2,2′,6,6′-tetra(2-ethylthienyl)-4,4′-dithiobispyranylidene

[0203] Under an inert gas atmosphere, 0.6 ml (2.4 mmol, 1 eq.) of tributyl phosphine is added to a violet suspension of 1.0 g (2.4 mmol, 1 eq.) of 2,6-di(5-ethylthienyl)thiopyrylium perchlorate in 50 ml of dried acetonitrile. The mixture changes color to gray and is stirred for 2.5 h at room temperature. Then 2.1 ml (12.0 mmol, 5 eq.) of N,N-diisopropylethylamine is added. The mixture is boiled under reflux at 95° C. for 2 h under an inert gas atmosphere and allowed to stand overnight. The product is obtained in the form of black crystals after filtration, washing with acetonitrile and drying in air.

##STR00020##

[0204] Molecular formula: C.sub.34H.sub.32S.sub.6 (632.08 g/mol)

[0205] Yield: 0.46 g (0.73 mmol, 61%)

[0206] ESI-MS: m/z 632 [M].sup.+

[0207] Absorption (DMF): α.sub.max=521 nm (c=72122 Lmol.sup.−1cm.sup.−1)

[0208] Melting point: 253° C.

[0209] .sup.1H-NMR (500 MHz, pyridine, ppm): δ=7.41 (s, 1H), 7.34 (d, J=3.6 Hz, 1H), 6.80 (d, J=3.6 Hz, 1H), 2.70 (q, J=7.5 Hz, 2H), 1.17 (t, J=7.5 Hz, 3H).

[0210] .sup.13C-NMR (125.75 MHz, benzene, ppm): δ=147.99, 139.99, 127.12, 125.02, 124.74, 124.42, 119.13, 24.16, 16.34.

[0211] FIG. 1 shows the UV-Vis absorption spectra of the thienyl-substituted bispyranylidenes and dithiobispyranilidenes in dimethylformamide (DMF). The curves are normalized to the strongest π-π* transition in each case. For the thienyl-substituted bispyranylidenes, the absorption band is split into two peaks and exhibits two red-shifted shoulders of low intensity. The thienyl-substituted dithiobispyranilidenes exhibit an absorption band with an approximately 100 nm red-shifted Amax compared to the equivalent thienyl-substituted bispyranylidenes. Furthermore, the methyl- or ethyl-substituted thienyl compounds exhibit a red shift compared to the unsubstituted thienyl compounds.

Synthesis Recipe for 1,5-bis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl])pentane-1,5-dione

[0212] 2.33 g AlCl.sub.3 is suspended with 20 ml dry DCM under intense stirring and cooled with ice. Under ice cooling, a solution of 2.72 g 5-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl, 1.4 g glutaryl chloride and 20 ml DCM is slowly added. Subsequently, stirring is continued for 24 h at room temperature.

##STR00021##

[0213] Molecular formula: C.sub.19H.sub.20O.sub.6S.sub.2 (408.48 g/mol)

[0214] Yield: 2.7 g (80%)

[0215] ESI-MS: m/z 409.1 [MH].sup.+

Synthesis Recipe for 2,6-bis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl])-thiopyrylium-perchlorate

[0216] 2.5 g of 1,5-bis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl])pentane-1,5-dione, 2.1 g of P2S10, and 3.9 g of LiClO4 are heated in 80 ml of glacial acetic acid for 3 h under reflux. After cooling and allowing to stand overnight, a purple solid is aspirated and washed with ether.

##STR00022##

[0217] Molecular formula: C.sub.19H.sub.17ClO.sub.8S.sub.3 (504.98 g/mol)

[0218] Yield: 1.92 g (77%)

[0219] ESI-MS: m/z 405.1 [M-C104].sup.+

2,2′,6,6′-Tetrakis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-4,4′-dithiobispyranilidene

[0220] 1.5 g of the corresponding thiopyrylium salt is dissolved in 40 ml of acetonitrile under N.sub.2 purge, and 0.73 ml of PBu.sub.3 is added. This mixture is stirred for 2 h at room temperature, 1.5 ml of Hünig's base is added and heated for 2 h under reflux. After cooling, crystals are formed, which are aspirated and washed with a suitable solvent.

##STR00023##

[0221] Molecular formula: C.sub.38H.sub.32O.sub.8S.sub.6 (809.03 g/mol)

[0222] Yield: 0.88 g (73%)

[0223] ESI-MS: m/z 808.1 [M].sup.+

General Procedure for the Synthesis of Diselenobispyranilidenes

[0224] Diselenobispyranilidenes are accessible, for example, via selenopyranthiones from selenopyranones (Detty et al. 1985). 10 mmol of a corresponding selenopyranothione and 3 g of copper powder are heated at reflux for 16 h in 30 ml of toluene under stirring as well as inert gas. The reaction mixture is subjected to suitable workup and recrystallized from acetonitrile.

##STR00024##

General Procedure for the Synthesis of Unsymmetrical Bispyranilidenes

[0225] Unsymmetrical bispyranilidenes can be synthesized analogously to the symmetrical compounds via phosphonium salts in a two-step reaction according to Reynolds and Chen (Reynolds and Chen 1980). The thio(seleno)pyrylium salt can also be phosphonylated and then reacted with the pyrylium salt.

[0226] A solution of 10 mmol pyrylium salt in 25 ml acetonitrile is stirred at room temperature for 2 h until the intense yellow color disappears. The white precipitate is aspirated and washed with acetonitrile.

##STR00025##

[0227] In a second step, a suspension of 2 mmol of the corresponding phosphonium salt shown previously is cooled to −78° C. in 35 ml of THF under inert gas with stirring. 0.9 ml of 2.5 M n-BuLi is added slowly and stirred for another 5 min. Then, 2 mmol of the desired thio- or selenopyrylium salt is added and stirred for 1 h at −78° C. followed by the addition of 5 ml of triethylamine. The reaction mixture is slowly warmed to room temperature overnight and purified chromatographically. Good to very good yields can be achieved.

##STR00026##

Process for Trifluoromethylation

[0228] Negishi et al. describe a process for trifluoromethylation, whereby the compounds of the invention are prepared with perfluoroalkyl residues (Negishi et al. 2016).

Electrochemical Characterization

Cyclic Voltammetry, CV

[0229] Cyclic voltammetry using a potentiostat (Methrom, μ-Autolab) and a 3-electrode cell configuration is performed to measure oxidation and reduction potentials and further determine HOMO/LUMO energy levels. Tetrabutylammonium hexafluorophosphate in dried dimethylformamide (DMF) or dimethyl sulfoxide (DMSO) (0.1 M) is used as the electrolyte, a glass-platinum electrode is used as the working electrode, a platinum wire is used as the counter electrode, and Ag/AgCl is used as the pseudo-reference electrode. Ferrocene/ferrocenium is used as an internal standard to scale the measured potentials. All solvents are deoxygenated with nitrogen before measurement. The measurement is made in the range of −1 V to 1 V, with a scan rate of 50 mV/s and 100 mV/s. The sample is measured with a concentration of 1 mM/I.

Differential Scanning Calorimetry, DSC

[0230] Thermal characterization is performed by differential scanning calorimetry (DSC) to determine phase transitions, melting and decomposition temperatures. DSC is performed using Mettler-Toledo DSC 1 Star and a scan rate of 5 K/min under a nitrogen atmosphere.

Sublimation

[0231] The compounds are crystallized two to three times to increase purity. Sublimation is carried out by means of a 3-zone gradient furnace from VEB Hochvakuum Dresden.

Fabrication of the Optoelectronic Component

[0232] The optoelectronic component is fabricated, for example, by thermal evaporation under ultra-high vacuum (8 to 10 mbar) onto a glass substrate with a pre-patterned ITO contact (Thin Film Devices, USA). A layer of 4,7-diphenyl-1,10-phenanthroline (BPhen):Cs, C60, 2,2′,6,6′-tetrathienyl-4,4′-dithiobispyranylidene or 2,2′,6,6′-tetra(2-methylthienyl)-4,4′-dithiobispyranylidene:C60 (mixture 5% (m/m) in C60), N4,N4′-bis(9,9-dimethyl-9H-265-fluoren-2-yl)-N4,N4′-diphenylbiphenyl-4,4′-diamine (BF-DPB):F6-TCNNQ, 2,2′-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCNNQ) and Al is deposited on top. The device is characterized by the geometrical overlap of the lower and upper contacts with 6.44 m2. The organic region is bonded to a small glass substrate.

Sensitive External Quantum Efficiency (EQE) Measurements

[0233] External quantum efficiencies are measured using a monochromatic light source to generate a current in an organic solar cell (OSC) under short-circuit conditions. The resulting current is pre-amplified and analyzed using a lock-in amplifier (Signal Recovery 7280 DSP).

[0234] FIG. 2 shows the results of measuring the external quantum efficiency (EQE) and internal quantum efficiency (IQE) of the optoelectronic devices comprising mixtures of 2,2′,6,6′-tetrathienyl-4,4′-dithiobispyranylidene (reference) (circles) and 2,2′,6,6′-tetra(2-methylthienyl)-4,4′-dithiobispyranylidene (squares), respectively, and C.sub.60. The IQE was calculated in the spectral range from 425 nm to 525 nm (IQE=EQE−absorbance.sup.−1), and an average IQE was calculated assuming that the IQE is independent of the excitation wavelength.

[0235] Using the IQE and the density of the donor molecules in the 50 nm thin films, the EQE spectra are converted to the σ.sub.CT absorption profiles (FIG. 3). The methylated compounds show red-shifted CT absorption compared to the equivalent non-methylated compounds. The introduction of sulfur into the pyranilidene core increases the peak σ.sub.CT and f.sub.σ up to twofold.

CITED NON-PATENT LITERATURE

[0236] Bolag A, Mamada M, Nishida J, Yamashita Y (2009) Field-Effect Transistors Based on Tetraphenyldipyranylidenes and the Sulfur Analogues. Chem. Mater. 21, 4350-4352. [0237] Detty M R, Hassett J W, Murray B J, Reynolds G A (1985) Δ.sup.4,4-4-Chalcogenpyranyl-4H-Chalcogenapyrans. Tetrahedron 41, 4853-4859. [0238] Fabre C, Fugnitto R, Strzelecka H (1976) Sur la synthèse de dipyranylidènes. Comptes rendus des sèances de l'Académie des Sciences. Serie C, Sciences chimiques 282 (3), 175-177. [0239] Mabon G, Cariou M, Simonet J (1989) The cathodic coupling of heterocyclic activat-ed thioketones. A new and efficient route to π-donors (I)—the synthesis of polysubstituted bipyranylidenes from 4H-pyran 4-thiones. New journal of chemistry 13 (8-9), 601-607. [0240] Negishi K, Aikawa K, Mikami K (2016) Cyclic-Protected Hexafluoroacetone as an Air-Stable Liquid Reagent for Trifluoromethylations. European Journal of Organic Chemistry 23, 4099-4104. [0241] Reynolds G A, Chen C H (1980) Synthesis of unsymmetrical Δ.sup.4,4-4-bi-4H-pyrans and thiopyrans. Journal of Organic Chemistry 45, 2458-2459. [0242] Siegmund B, Mischok A, Benduhn J, Zeika O, Ullbrich S, Nehm F, Böhm M, Spoltore D, Fröb H, Körner C, Leo K, Vandewal K (2017) Organic narrowband near-infrared photodetectors based on intermolecular charge-transfer absorption. Nature Communications 8, 15421. [0243] Strezelecka H, Schoenfelder W, Rivory J (1979) Electrical and optical properties of conducting TCNQ salts. Molecular Crystals and Liquid Crystals 52, 307-317.