Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties Relationship
Carbazole derivatives, carbazole-containing polymers and iridium complexes are of interest due to many possible applications in photonics, electronics and biology, particularly as active or hole-transporting layers in organic as well as perovskite devices due to their interesting properties. Here, a...
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MDPI AG
2023-07-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/15/13/2932 |
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| author | Věra Cimrová Drahomír Výprachtický Aleš Růžička Veronika Pokorná |
| author_facet | Věra Cimrová Drahomír Výprachtický Aleš Růžička Veronika Pokorná |
| author_sort | Věra Cimrová |
| collection | DOAJ |
| description | Carbazole derivatives, carbazole-containing polymers and iridium complexes are of interest due to many possible applications in photonics, electronics and biology, particularly as active or hole-transporting layers in organic as well as perovskite devices due to their interesting properties. Here, a series of carbazole-fluorene conjugated copolymers with various substituents at the <i>N</i>-carbazole position (2-methoxycarbonylethyl, 2-carboxyethyl, 2-ethylhexyl, and nonan-2,4-dionatoiridium(III)bis(2-phenylpyridine-<i>N</i>,<i>C</i><sup>2′</sup>)-9-yl) was prepared by Suzuki coupling. Their photophysical, electrochemical and electroluminescence (EL) properties were studied. Effects of molecular weight and substituents attached to carbazole unit on their properties are reported. The carbazole-fluorene copolymers in dilute solutions exhibited intense photoluminescence (PL) emission in the blue spectral region with high PL quantum yields (78–87%) except for the copolymer with the iridium complex (23%). Similar PL spectra were observed in dilute solutions. More pronounced differences were found in thin film PL and EL properties due to excimer/aggregate formation. Light-emitting devices (LEDs) made of copolymers with 2-ethylhexyl as <i>N</i>-carbazole substituent exhibited efficient EL emission with the best performance and the lowest EL onset voltages (3–4 V), while the LEDs made of copolymers with other substituents were not as efficient, but showed anomalous behavior and memory effects in current-voltage characteristics promising also for bio-inspired electronics. |
| first_indexed | 2024-03-11T01:30:46Z |
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| id | doaj.art-de8b8bdf1ce641cf9f4b45f96579c6a5 |
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| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-11T01:30:46Z |
| publishDate | 2023-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-de8b8bdf1ce641cf9f4b45f96579c6a52023-11-18T17:22:15ZengMDPI AGPolymers2073-43602023-07-011513293210.3390/polym15132932Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties RelationshipVěra Cimrová0Drahomír Výprachtický1Aleš Růžička2Veronika Pokorná3Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Prague 6, Czech RepublicInstitute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Prague 6, Czech RepublicInstitute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Prague 6, Czech RepublicInstitute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Prague 6, Czech RepublicCarbazole derivatives, carbazole-containing polymers and iridium complexes are of interest due to many possible applications in photonics, electronics and biology, particularly as active or hole-transporting layers in organic as well as perovskite devices due to their interesting properties. Here, a series of carbazole-fluorene conjugated copolymers with various substituents at the <i>N</i>-carbazole position (2-methoxycarbonylethyl, 2-carboxyethyl, 2-ethylhexyl, and nonan-2,4-dionatoiridium(III)bis(2-phenylpyridine-<i>N</i>,<i>C</i><sup>2′</sup>)-9-yl) was prepared by Suzuki coupling. Their photophysical, electrochemical and electroluminescence (EL) properties were studied. Effects of molecular weight and substituents attached to carbazole unit on their properties are reported. The carbazole-fluorene copolymers in dilute solutions exhibited intense photoluminescence (PL) emission in the blue spectral region with high PL quantum yields (78–87%) except for the copolymer with the iridium complex (23%). Similar PL spectra were observed in dilute solutions. More pronounced differences were found in thin film PL and EL properties due to excimer/aggregate formation. Light-emitting devices (LEDs) made of copolymers with 2-ethylhexyl as <i>N</i>-carbazole substituent exhibited efficient EL emission with the best performance and the lowest EL onset voltages (3–4 V), while the LEDs made of copolymers with other substituents were not as efficient, but showed anomalous behavior and memory effects in current-voltage characteristics promising also for bio-inspired electronics.https://www.mdpi.com/2073-4360/15/13/2932carbazole-fluorene copolymersiridium complexsynthesisphotophysicselectrochemistryelectroluminescence |
| spellingShingle | Věra Cimrová Drahomír Výprachtický Aleš Růžička Veronika Pokorná Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties Relationship Polymers carbazole-fluorene copolymers iridium complex synthesis photophysics electrochemistry electroluminescence |
| title | Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties Relationship |
| title_full | Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties Relationship |
| title_fullStr | Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties Relationship |
| title_full_unstemmed | Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties Relationship |
| title_short | Carbazole-Fluorene Copolymers with Various Substituents at the Carbazole Nitrogen: Structure—Properties Relationship |
| title_sort | carbazole fluorene copolymers with various substituents at the carbazole nitrogen structure properties relationship |
| topic | carbazole-fluorene copolymers iridium complex synthesis photophysics electrochemistry electroluminescence |
| url | https://www.mdpi.com/2073-4360/15/13/2932 |
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