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Synthesis, photophysical and electroluminescent properties of 1,3-diphenyl-1H-benzo[g]pyrazolo[3,4–b]quinoxaline
Materials Letters 138 (2015) 9–12
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Synthesis, photophysical and electroluminescent properties of 1,3-diphenyl-1H-benzo[g]pyrazolo[3,4–b]quinoxaline Andrzej Danel a, Bożena Jarosz a, Paweł Karasiński b,n, Bouchta Sahraoui c, Paweł Armatys d a
Department of Chemistry and Physics, H.Kołłątaj University of Agriculture, Balicka Str. 122, Krakow, Poland Department of Optoelectronics, Silesian University of Technology, B. Krzywoustego Str. 2, 44-100 Gliwice, Poland c LUNAM Université, Université d’Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex, France d AGH – University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Kraków, Poland b
art ic l e i nf o
a b s t r a c t
Article history: Received 10 September 2014 Accepted 20 September 2014 Available online 28 September 2014
Experimental investigations of electroluminescence spectra for new azaacene derivative have been performed. Azaacene was used as dopant in PVK matrices in electroluminescence devices with ITO/ PEDOT:PSS/active layer/Ca/Al light-emitting diode configuration. The yellow emission was obtained with the electroluminance of 1530 cd/m2 at 15.0V. & 2014 Elsevier B.V. All rights reserved.
Keywords: OLED 1H-benzo[g]pyrazolo [34-b]quinoxaline PVK.
1. Introduction The organic electroluminescent devices are good candidates to replace conventional sources of lightning in the future. In case of small displays some of examples can be found in digital cameras, mobile phones, tablets or OLED TV screens. Many classes of organic compounds are applied for their construction. One of the most important is nitrogen-containing heterocyclic one. They can be used as hole- or electron transporting materials and as luminophores too. In the recent years quite a lot of review papers were devoted to this subject [1,2]. In the last few years our scientific interests were focused on the synthesis and application of 1H-pyrazolo[3,4–b]quinolines (PQs, Fig. 1) in electroluminescent devices. In spite of the fact that the first representative compound of this system was synthesized almost 100 years ago, the photophysical properties of PQs were being investigated just by the end of the 90s [3]. Majority of them exhibit high quantum yield of luminescence in solution as in the solid state as well so some of them were used as fluorescent sensors [4]. Besides they are thermally stable and exhibit high glass transition Tg and decomposition Td temperatures [5]. Due to these properties we have chosen them as luminophores for fabrication of OLED. Our first devices possessed double- or three-layered structure and were fabricated by vacuum evaporation of subsequent layers [6,7]. In one case as a green dopant 6-N,N-diethyl-1-methyl-3phenyl-1H-pyrazolo[3,4–b]quinoline was chosen. The device with
n
Corresponding author. E-mail address: [email protected] (P. Karasiński).
http://dx.doi.org/10.1016/j.matlet.2014.09.079 0167-577X/& 2014 Elsevier B.V. All rights reserved.
configuration ITO/NPD/NPD:16%PQ/TPBI/Mg/Ag exhibited luminance of 37 000 cd/m2 at 10.0 V with a maximum power efficiency of 4.2 lm/W and external quantum efficiency (EQE) of 1.6% respectively [7]. The other devices were fabricated using spin-coating techniques. The hole transporting material like poly(9-N-vinylcarbazole) PVK was sandwiched between an ITO anode and a Mg/Ag cathode. PVK was doped with pyrazoloquinoline without or with electron-transporting material like oxadiazole derivative PBD [8]. 1H-Pyrazolo[3,4–b]quinolines were also copolymerized with 9-Nvinylcarbazole and these polymers were used for fabrication of single layer OLED [9] The next class of compounds we are interested in are 1H-pyrazolo[3,4–b]quinoxalines PQX which are green light emitters (Fig. 1). Similarly, like in the case of PQs the PQXs were barely investigated from photophysical point of view. Almost all of the papers concerning these class of compounds were focused on their biological activity. There are only few publications on PQX as luminophores for OLED. For example Lee et al. [10] applied 1H-pyrazoloquinoxalines with N,N-dialkyl substituent in multilayered OLED as emitters. These green dopants show emission at 520–540 nm in solution with high quantum yield. The devices with configuration ITO/NPB/AlQ3-PQX/AlQ3/ MgAg emitted bright green light at 530–545 nm with efficiencies 7.5–9.5 cd/A [10]. We synthesized 6-N,N-diarylsubstituted PQX and applied in electroluminescent cells as dopants in PVK matrix [11]. PQXs were also used in single layered photovoltaic devices with configuration ITO/PEDOT-PSS/P3OT-dopant/Mg/Ag. After being illuminated with the light of intensity 1.3 mW/cm2 the photovoltaic efficiency of these devices reached 0.08–0.83% depending on the substituent [12]. Just recently we have
10
A. Danel et al. / Materials Letters 138 (2015) 9–12
synthesized another nitrogen heterocyclic system which belongs to benzo[f]-, benzo[g]- and benzo[h]pyrazolo[3,4–b]quinoxalines. To the best of our knowledge, none of them were employed in OLED or organic photovoltaic devices so far. Here we present the preliminary results for 1H-benzo[h]pyrazolo[3,4–b]quinoxalines in a single layer organic electroluminescent device.
2. Results and discussion The synthetic routes for these compounds are shown in Fig. 2. 2,5-Diphenyl-4H-pyrazol-3-one 1 was reacted with p-nitroso-N, N-dimethylaniline yielding 4-(4-dimetylaminophenyl)imino-2, 5-diphenyl-pyrazol-3-one 2. Hydrolysis of 2 with diluted sulfuric acid gave the starting materials like 2,5-diphenylpyrazole-3, 4-dione 3 [13]. Dione 3 was heated with 3a or 3b in glacial acetic acid for 24 hours. In case of 3a, we obtained 1,3-diphenyl-1Hbenzo[g]pyrazolo[3,4–b]quinoxaline 7. When 3b was taken out the inseparable mixture of benzo[f]- 5 and benzo[h]pyrazolo[3,4–b] quinoxaline 6 was obtained. Because of this fact the synthesis of 5 and 6 was carried out with the application of different synthetic procedure and the results will be published separately.
Fig. 1. The structures of 1H-pyrazolo[3,4–b]quinoline and 1H-pyrazolo[3,4–b] quinoxaline PQX.
The 1,3-disubstituted 1H-pyrazolo[3,4–b]quinolines (R1,2 ¼ Me, Ph, R3 ¼Ph, H, R4 ¼ H) exhibit blue or blue-green emission in the range of 430–480 nm depending on the solvent. A small bathochromic shift is observed in polar one [3]. On the other hand, the introduction of additional nitrogen atom into the middle ring like in 1H-pyrazolo[3,4–b]quinoxaline induces strong bathochromic shift of 70–80 nm and PQXs are predominantly green emitters [14]. The absorption and photoluminescent spectra recorded for the tetrahydrofurane solution of 7 is displayed in Fig. 3. All spectra were recorded at 1 nm resolution. It can be noticed that absorption covers a broad range of spectra (200–580 nm). Due to additional carbocyclic ring in the azaacene system of 7 both
Fig. 3. UV–vis absorption (A) and photoluminescence spectra of 7 (B).
Fig. 2. (a) Na2CO3/p-nitroso-N,N-dimethylaniline; (b) dil. H2SO4/heating; (c) CH3COOH/boiling/24 h.
A. Danel et al. / Materials Letters 138 (2015) 9–12
11
To investigate electroluminescent properties of 7, we fabricated a device with configuration ITO/PEDOT-PSS/PVK þ7/Mg/Ag. In response to an applied potential the device showed yellow emission with a peak at 548 nm with full width at half maximum FWHM ¼88 nm (Fig. 4). Current-voltage and electroluminescence-voltage characteristics are depicted in the Fig. 5a and b, respectively. It should be noted that the turn-on voltage for investigated device is relatively high due to the lack of additional electron transporting material. Though quinoxaline derivatives are frequently used as electron transporting materials, the next experiments for 5, 6 and 7 will be carried out with an additional electrontransporting dopant or layer to reduce the turn-on voltage.
3. Synthesis of 1,3-diphenyl-1H-benzo[g]pyrazolo[3,4–b] quinoxaline 7 Fig. 4. Electroluminescent spectra of 1,3-diphenyl-1H-benzo[g]pyrazolo[3,4–b]quinoxaline 7.
Equimolar amounts of 2,3-diaminonaphtalene (0.01 mol, 0.158 g) and 2,5-diphenylpyrazole-3,4-dione (0.01 mol, 0.25 g) and 25 mL of glacial acetic acid were placed in a round bottomed flask (50 mL) and refluxed for 24 hours. The reaction mixture was cooled and the resulting dark red precipitate was filtered off, dried and purified on column filled with alumina using toluene as eluent. Dark red crystals, 250 mg, 67%, mp. 238 1C (toluene). 1 H NMR (300 MHz, CDCl3, δ ppm): 9.00(s, 1H), 8.81-8.77(m, 3H), 8.61-8.58(m, 2H), 8.14-8.01(m, 2H), 7.62-7.46 (m, 7H), 7.347.29(m, 1H). Anal. calcd for C25H16N4: C 80.63%; H 4.33%; N 15.03%. Found 80.56%; H 4.25%; N 14.97%.
4. Conclusions In conclusion, we report a simple electroluminescent device based on a new azaacene derivative 7. The single layer device has been constructed with spin-coating technique using 7 as dopant in PVK matrices. The yellow emission was obtained with the luminance of 800 cd/m2. We presume that further study of these class of dyes let us to synthesize orange or red luminophores (emission maximum wavelength λmax 4610 nm) for doped OLED.
Acknowledgment This work was supported by the National Science Centre on the basis of decision DEC-2011/03/B/ST7/03538. References
Fig. 5. (a) Current-voltage and (b) electroluminescence-voltage characteristics for device ITO/PEDOT-PSS/PVKþ 7/Mg/Ag.
absorption and photoluminescence spectra are red-shifted in the comparison with 1,3-diphenyl-1H-pyrazolo[3,4–b]quinoxaline. The emission of angular equivalents of 5 or 6 is almost the same like 1,3-diphenyl-1H-pyrazolo[3,4–b]quinoxaline (Fig. 1 PQX, R1,2 ¼Ph) and the bathochromic shift is not observed.
[1] Hughes G, Bryce MR. Electron-transporting materials for organic electroluminescent and electrophosphorescent devices. J MaterChem 2005;15:94–107. [2] Grimsdale AG, Chan KL, Martin RE, Jokisz PG, Holmes AB. Synthesis of lightemitting conjugated polymers for applications in electroluminescent devices. Chem Rev 2009;109:897–1091. [3] Musierowicz A, Niementowski S, Tomasik Z. Kondensacje fenylo-1-metylo-3okso-5[dwuhydro-4.5-pyrazolu] i [chloro-2]-fenylo-1-metylo-3-okso-5[dwuhydro-4,5-pyrazolu] z o-aminobenzaldehydem. Rocz Chem 1928;8:325–44. [4] Mac M, Uchacz T, Danel A, Musiolik H. Applications of fluorescent sensor based on 1H-pyrazolo[3,4-b]quinoline in analytical chemistry. J Fluoresc 2013;23(6):1207–15. [5] Chen C-H, Wu F-I, Shu C-F, Chien C-H, Tao Y-T. Spirobifluorene-based pyrazoloquinolines: efficient blue electroluminescent materials. J Mater Chem 2004;14:1585–9. [6] Funaki J, Imai K, Araki K, Danel A, Tomasik P. 1H-Pyrazolo[3,4-b]quinolines and their performance in electroluminescent devices. Pol J Chem 2004;78: 843–50. [7] Tao Y-T, Balasubramaniam E, Danel A, Jarosz B, Tomasik P. Sharp green electroluminescence from 1H-pyrazolo[3,4-b]quinoline-based light-emitting diodes. Appl Phys Lett 2000;77:1575–7.
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A. Danel et al. / Materials Letters 138 (2015) 9–12
[8] Łuczyńska B, Dobruchowska E, Głowacki I, Ulański J, Jasier F, Yang X, et al. Poly (N-vinylcarbazole) doped with a pyrazoloquinoline dye: a deep blue lightemitting composite for light-emitting diode applications. J Appl Phys 2006;99: 024505-1–4. [9] Nizioł J, Danel A, Jarosz B, Armatys P, Wrotniak M, Kajzar F, et al. Synthesis and electro-optic properties of Pirazolo[3,4-b]Chinoline – PVK copolymers. Mol Cryst Liq Crys 2006;447:181–8. [10] Wang P, Xie Z, Hong Z, Tang J, Wong O, Lee C-S, et al. Synthesis, photoluminescence and electroluminescence of new 1H-pyrazolo[3,4-b]quinoxaline derivatives. J Mater Chem 2003;13:1894–9. [11] Gondek E, Danel A, Kityk IV, Sanetra J, Nizioł J. Spectral features and parameters of some 1H-Pyrazolo[3,4-b]quinoxaline derivative dye chromophores. Spectrosc Lett 2009;42:136–41.
[12] Gondek E, Djaoued Y, Robichaud J, Karasiński P, Kityk IV, Danel A, et al. Influence of TiO2 nanoparticles on the photovoltaic efficiency of the ITO/ PEDOT:PSS/fluorine copolymers/polythiphene:TiO2/Al architecture. J Mater Sci Mater Electron 2012;23:2057–64. [13] Sachs F, Becherescu P. Ueber ketopyrazolone. II 1.3-Diphenylpyrazolindiou(4.5). Ber Dtsch Chem Ges 1903;36:1132. [14] Gondek E, Danel A, Kityk IV. 6-N,N-diarylsubstituted 1H-pyrazolo[3,4-b] quinoxalines-novel materials for single-layered photovoltaic devices. J Mater Sci Mater Electron 2009;20:461–8.
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Synthesis, photophysical and electroluminescent properties of 1,3-diphenyl-1H-benzo[g]pyrazolo[3,4–b]quinoxaline Andrzej Danel a, Bożena Jarosz a, Paweł Karasiński b,n, Bouchta Sahraoui c, Paweł Armatys d a
Department of Chemistry and Physics, H.Kołłątaj University of Agriculture, Balicka Str. 122, Krakow, Poland Department of Optoelectronics, Silesian University of Technology, B. Krzywoustego Str. 2, 44-100 Gliwice, Poland c LUNAM Université, Université d’Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex, France d AGH – University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Kraków, Poland b
art ic l e i nf o
a b s t r a c t
Article history: Received 10 September 2014 Accepted 20 September 2014 Available online 28 September 2014
Experimental investigations of electroluminescence spectra for new azaacene derivative have been performed. Azaacene was used as dopant in PVK matrices in electroluminescence devices with ITO/ PEDOT:PSS/active layer/Ca/Al light-emitting diode configuration. The yellow emission was obtained with the electroluminance of 1530 cd/m2 at 15.0V. & 2014 Elsevier B.V. All rights reserved.
Keywords: OLED 1H-benzo[g]pyrazolo [34-b]quinoxaline PVK.
1. Introduction The organic electroluminescent devices are good candidates to replace conventional sources of lightning in the future. In case of small displays some of examples can be found in digital cameras, mobile phones, tablets or OLED TV screens. Many classes of organic compounds are applied for their construction. One of the most important is nitrogen-containing heterocyclic one. They can be used as hole- or electron transporting materials and as luminophores too. In the recent years quite a lot of review papers were devoted to this subject [1,2]. In the last few years our scientific interests were focused on the synthesis and application of 1H-pyrazolo[3,4–b]quinolines (PQs, Fig. 1) in electroluminescent devices. In spite of the fact that the first representative compound of this system was synthesized almost 100 years ago, the photophysical properties of PQs were being investigated just by the end of the 90s [3]. Majority of them exhibit high quantum yield of luminescence in solution as in the solid state as well so some of them were used as fluorescent sensors [4]. Besides they are thermally stable and exhibit high glass transition Tg and decomposition Td temperatures [5]. Due to these properties we have chosen them as luminophores for fabrication of OLED. Our first devices possessed double- or three-layered structure and were fabricated by vacuum evaporation of subsequent layers [6,7]. In one case as a green dopant 6-N,N-diethyl-1-methyl-3phenyl-1H-pyrazolo[3,4–b]quinoline was chosen. The device with
n
Corresponding author. E-mail address: [email protected] (P. Karasiński).
http://dx.doi.org/10.1016/j.matlet.2014.09.079 0167-577X/& 2014 Elsevier B.V. All rights reserved.
configuration ITO/NPD/NPD:16%PQ/TPBI/Mg/Ag exhibited luminance of 37 000 cd/m2 at 10.0 V with a maximum power efficiency of 4.2 lm/W and external quantum efficiency (EQE) of 1.6% respectively [7]. The other devices were fabricated using spin-coating techniques. The hole transporting material like poly(9-N-vinylcarbazole) PVK was sandwiched between an ITO anode and a Mg/Ag cathode. PVK was doped with pyrazoloquinoline without or with electron-transporting material like oxadiazole derivative PBD [8]. 1H-Pyrazolo[3,4–b]quinolines were also copolymerized with 9-Nvinylcarbazole and these polymers were used for fabrication of single layer OLED [9] The next class of compounds we are interested in are 1H-pyrazolo[3,4–b]quinoxalines PQX which are green light emitters (Fig. 1). Similarly, like in the case of PQs the PQXs were barely investigated from photophysical point of view. Almost all of the papers concerning these class of compounds were focused on their biological activity. There are only few publications on PQX as luminophores for OLED. For example Lee et al. [10] applied 1H-pyrazoloquinoxalines with N,N-dialkyl substituent in multilayered OLED as emitters. These green dopants show emission at 520–540 nm in solution with high quantum yield. The devices with configuration ITO/NPB/AlQ3-PQX/AlQ3/ MgAg emitted bright green light at 530–545 nm with efficiencies 7.5–9.5 cd/A [10]. We synthesized 6-N,N-diarylsubstituted PQX and applied in electroluminescent cells as dopants in PVK matrix [11]. PQXs were also used in single layered photovoltaic devices with configuration ITO/PEDOT-PSS/P3OT-dopant/Mg/Ag. After being illuminated with the light of intensity 1.3 mW/cm2 the photovoltaic efficiency of these devices reached 0.08–0.83% depending on the substituent [12]. Just recently we have
10
A. Danel et al. / Materials Letters 138 (2015) 9–12
synthesized another nitrogen heterocyclic system which belongs to benzo[f]-, benzo[g]- and benzo[h]pyrazolo[3,4–b]quinoxalines. To the best of our knowledge, none of them were employed in OLED or organic photovoltaic devices so far. Here we present the preliminary results for 1H-benzo[h]pyrazolo[3,4–b]quinoxalines in a single layer organic electroluminescent device.
2. Results and discussion The synthetic routes for these compounds are shown in Fig. 2. 2,5-Diphenyl-4H-pyrazol-3-one 1 was reacted with p-nitroso-N, N-dimethylaniline yielding 4-(4-dimetylaminophenyl)imino-2, 5-diphenyl-pyrazol-3-one 2. Hydrolysis of 2 with diluted sulfuric acid gave the starting materials like 2,5-diphenylpyrazole-3, 4-dione 3 [13]. Dione 3 was heated with 3a or 3b in glacial acetic acid for 24 hours. In case of 3a, we obtained 1,3-diphenyl-1Hbenzo[g]pyrazolo[3,4–b]quinoxaline 7. When 3b was taken out the inseparable mixture of benzo[f]- 5 and benzo[h]pyrazolo[3,4–b] quinoxaline 6 was obtained. Because of this fact the synthesis of 5 and 6 was carried out with the application of different synthetic procedure and the results will be published separately.
Fig. 1. The structures of 1H-pyrazolo[3,4–b]quinoline and 1H-pyrazolo[3,4–b] quinoxaline PQX.
The 1,3-disubstituted 1H-pyrazolo[3,4–b]quinolines (R1,2 ¼ Me, Ph, R3 ¼Ph, H, R4 ¼ H) exhibit blue or blue-green emission in the range of 430–480 nm depending on the solvent. A small bathochromic shift is observed in polar one [3]. On the other hand, the introduction of additional nitrogen atom into the middle ring like in 1H-pyrazolo[3,4–b]quinoxaline induces strong bathochromic shift of 70–80 nm and PQXs are predominantly green emitters [14]. The absorption and photoluminescent spectra recorded for the tetrahydrofurane solution of 7 is displayed in Fig. 3. All spectra were recorded at 1 nm resolution. It can be noticed that absorption covers a broad range of spectra (200–580 nm). Due to additional carbocyclic ring in the azaacene system of 7 both
Fig. 3. UV–vis absorption (A) and photoluminescence spectra of 7 (B).
Fig. 2. (a) Na2CO3/p-nitroso-N,N-dimethylaniline; (b) dil. H2SO4/heating; (c) CH3COOH/boiling/24 h.
A. Danel et al. / Materials Letters 138 (2015) 9–12
11
To investigate electroluminescent properties of 7, we fabricated a device with configuration ITO/PEDOT-PSS/PVK þ7/Mg/Ag. In response to an applied potential the device showed yellow emission with a peak at 548 nm with full width at half maximum FWHM ¼88 nm (Fig. 4). Current-voltage and electroluminescence-voltage characteristics are depicted in the Fig. 5a and b, respectively. It should be noted that the turn-on voltage for investigated device is relatively high due to the lack of additional electron transporting material. Though quinoxaline derivatives are frequently used as electron transporting materials, the next experiments for 5, 6 and 7 will be carried out with an additional electrontransporting dopant or layer to reduce the turn-on voltage.
3. Synthesis of 1,3-diphenyl-1H-benzo[g]pyrazolo[3,4–b] quinoxaline 7 Fig. 4. Electroluminescent spectra of 1,3-diphenyl-1H-benzo[g]pyrazolo[3,4–b]quinoxaline 7.
Equimolar amounts of 2,3-diaminonaphtalene (0.01 mol, 0.158 g) and 2,5-diphenylpyrazole-3,4-dione (0.01 mol, 0.25 g) and 25 mL of glacial acetic acid were placed in a round bottomed flask (50 mL) and refluxed for 24 hours. The reaction mixture was cooled and the resulting dark red precipitate was filtered off, dried and purified on column filled with alumina using toluene as eluent. Dark red crystals, 250 mg, 67%, mp. 238 1C (toluene). 1 H NMR (300 MHz, CDCl3, δ ppm): 9.00(s, 1H), 8.81-8.77(m, 3H), 8.61-8.58(m, 2H), 8.14-8.01(m, 2H), 7.62-7.46 (m, 7H), 7.347.29(m, 1H). Anal. calcd for C25H16N4: C 80.63%; H 4.33%; N 15.03%. Found 80.56%; H 4.25%; N 14.97%.
4. Conclusions In conclusion, we report a simple electroluminescent device based on a new azaacene derivative 7. The single layer device has been constructed with spin-coating technique using 7 as dopant in PVK matrices. The yellow emission was obtained with the luminance of 800 cd/m2. We presume that further study of these class of dyes let us to synthesize orange or red luminophores (emission maximum wavelength λmax 4610 nm) for doped OLED.
Acknowledgment This work was supported by the National Science Centre on the basis of decision DEC-2011/03/B/ST7/03538. References
Fig. 5. (a) Current-voltage and (b) electroluminescence-voltage characteristics for device ITO/PEDOT-PSS/PVKþ 7/Mg/Ag.
absorption and photoluminescence spectra are red-shifted in the comparison with 1,3-diphenyl-1H-pyrazolo[3,4–b]quinoxaline. The emission of angular equivalents of 5 or 6 is almost the same like 1,3-diphenyl-1H-pyrazolo[3,4–b]quinoxaline (Fig. 1 PQX, R1,2 ¼Ph) and the bathochromic shift is not observed.
[1] Hughes G, Bryce MR. Electron-transporting materials for organic electroluminescent and electrophosphorescent devices. J MaterChem 2005;15:94–107. [2] Grimsdale AG, Chan KL, Martin RE, Jokisz PG, Holmes AB. Synthesis of lightemitting conjugated polymers for applications in electroluminescent devices. Chem Rev 2009;109:897–1091. [3] Musierowicz A, Niementowski S, Tomasik Z. Kondensacje fenylo-1-metylo-3okso-5[dwuhydro-4.5-pyrazolu] i [chloro-2]-fenylo-1-metylo-3-okso-5[dwuhydro-4,5-pyrazolu] z o-aminobenzaldehydem. Rocz Chem 1928;8:325–44. [4] Mac M, Uchacz T, Danel A, Musiolik H. Applications of fluorescent sensor based on 1H-pyrazolo[3,4-b]quinoline in analytical chemistry. J Fluoresc 2013;23(6):1207–15. [5] Chen C-H, Wu F-I, Shu C-F, Chien C-H, Tao Y-T. Spirobifluorene-based pyrazoloquinolines: efficient blue electroluminescent materials. J Mater Chem 2004;14:1585–9. [6] Funaki J, Imai K, Araki K, Danel A, Tomasik P. 1H-Pyrazolo[3,4-b]quinolines and their performance in electroluminescent devices. Pol J Chem 2004;78: 843–50. [7] Tao Y-T, Balasubramaniam E, Danel A, Jarosz B, Tomasik P. Sharp green electroluminescence from 1H-pyrazolo[3,4-b]quinoline-based light-emitting diodes. Appl Phys Lett 2000;77:1575–7.
12
A. Danel et al. / Materials Letters 138 (2015) 9–12
[8] Łuczyńska B, Dobruchowska E, Głowacki I, Ulański J, Jasier F, Yang X, et al. Poly (N-vinylcarbazole) doped with a pyrazoloquinoline dye: a deep blue lightemitting composite for light-emitting diode applications. J Appl Phys 2006;99: 024505-1–4. [9] Nizioł J, Danel A, Jarosz B, Armatys P, Wrotniak M, Kajzar F, et al. Synthesis and electro-optic properties of Pirazolo[3,4-b]Chinoline – PVK copolymers. Mol Cryst Liq Crys 2006;447:181–8. [10] Wang P, Xie Z, Hong Z, Tang J, Wong O, Lee C-S, et al. Synthesis, photoluminescence and electroluminescence of new 1H-pyrazolo[3,4-b]quinoxaline derivatives. J Mater Chem 2003;13:1894–9. [11] Gondek E, Danel A, Kityk IV, Sanetra J, Nizioł J. Spectral features and parameters of some 1H-Pyrazolo[3,4-b]quinoxaline derivative dye chromophores. Spectrosc Lett 2009;42:136–41.
[12] Gondek E, Djaoued Y, Robichaud J, Karasiński P, Kityk IV, Danel A, et al. Influence of TiO2 nanoparticles on the photovoltaic efficiency of the ITO/ PEDOT:PSS/fluorine copolymers/polythiphene:TiO2/Al architecture. J Mater Sci Mater Electron 2012;23:2057–64. [13] Sachs F, Becherescu P. Ueber ketopyrazolone. II 1.3-Diphenylpyrazolindiou(4.5). Ber Dtsch Chem Ges 1903;36:1132. [14] Gondek E, Danel A, Kityk IV. 6-N,N-diarylsubstituted 1H-pyrazolo[3,4-b] quinoxalines-novel materials for single-layered photovoltaic devices. J Mater Sci Mater Electron 2009;20:461–8.