| Title: |
Stereoisomeric Homo‐ and Hetero‐Binuclear Iridium(III) Complexes with 3‐Oxidopicolinate Bridging Ligand and Their Application in OLEDs |
| Authors: |
Bejoymohandas, Kochan Sathyaseelan; Baschieri, Andrea; Reginato, Francesco; Toffanin, Stefano; Prosa, Mario; Bandini, Elisa; Mazzanti, Andrea; Monti, Filippo |
| Contributors: |
European Commission; H2020 European Research Council; H2020 Marie Skłodowska-Curie Actions; Ministero dell'Istruzione e del Merito |
| Source: |
Advanced Optical Materials ; volume 12, issue 33 ; ISSN 2195-1071 2195-1071 |
| Publisher Information: |
Wiley |
| Publication Year: |
2024 |
| Collection: |
Wiley Online Library (Open Access Articles via Crossref) |
| Description: |
The small and simple 3‐hydroxypyridine‐2‐carboxylic acid ( Hpic‐OH ) is explored as asymmetric bridging ligand for the synthesis of neutral binuclear cyclometalated iridium(III) complexes. Once fully deprotonated the picO 2– ligand can act as ancillary ligand toward two iridium centers adopting both the N^O – and O^O – chelation modes. To tune the energy of the excited states within such binuclear complexes, the 2‐(2,4‐difluorophenyl)pyridine ( Hdfppy ) and the 2‐phenylbenzothiazole ( Hpbtz ) are used as cyclometalating ligands to respectively obtain both blue‐ or orange‐emissive homo‐cyclometalated complexes ( BB and YY , with formula [Ir(dfppy) 2 ] 2 (picO) and [Ir(pbtz) 2 ] 2 (picO), respectively). Moreover, for the first time, short‐bridged hetero‐cyclometalated binuclear complexes are also obtained ( BY and YB , with formula [Ir(dfppy) 2 ](picO)[Ir(pbtz) 2 ] and [Ir(pbtz) 2 ](picO)[Ir(dfppy) 2 ]). Depending on the reciprocal arrangement of the cyclometalating ligands on the two sides of the small picolinate bridge, two couples of diastereoisomers are obtained and efficiently separated, as proved by combined NMR and DFT studies. The reported binuclear complexes are highly emissive with photoluminescence quantum yields (PLQYs) up to 67%, which are comparable to those of their mononuclear analogues ( B and Y ). Due to the full reversibility of their redox processes, all the complexes are also tested in solution‐processed organic light‐emitting diodes, providing unique OLEDs based on hetero‐binuclear cyclometalated iridium(III) complexes. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1002/adom.202401586 |
| Availability: |
https://doi.org/10.1002/adom.202401586; https://onlinelibrary.wiley.com/doi/pdf/10.1002/adom.202401586 |
| Rights: |
http://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.42840C06 |
| Database: |
BASE |