A counterion study of a series of [Cu(P^P)(N^N)][A] compounds with bis(phosphane) and 6-methyl and 6,6′-dimethyl-substituted 2,2′-bipyridine ligands for light-emitting electrochemical cells†
| Autor: | Daniel Tordera, Marco Meyer, Edwin C. Constable, Alessandro Prescimone, Lorenzo Mardegan, Henk J. Bolink, Michele Sessolo, Catherine E. Housecroft |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Trifluoromethyl Xantphos chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Copper Medicinal chemistry 2 2'-Bipyridine 0104 chemical sciences 3. Good health Inorganic Chemistry Electroquímica chemistry.chemical_compound Chemistry chemistry Ionic liquid Luminophore Counterion 0210 nano-technology Single crystal |
| Zdroj: | Dalton Transactions (Cambridge, England : 2003) Meyer, Marco Mardegan, Lorenzo Tordera Salvador, Daniel Prescimone, Alessandro Sessolo, Michele Bolink, Henk Constable, Edwin C. Housecroft, Catherine E. 2021 A counterion study of a series of [Cu(P^P)(N^N)][A] compounds with bis(phosphane) and 6-methyl and 6,6'-dimethyl-substituted 2,2'-bipyridine ligands for light-emitting electrochemical cells Dalton Transactions 50 17920 17934 RODERIC. Repositorio Institucional de la Universitat de Valéncia instname Dalton Transactions |
| ISSN: | 1477-9234 1477-9226 |
| Popis: | The syntheses and characterisations of a series of heteroleptic copper(i) compounds [Cu(POP)(Mebpy)][A], [Cu(POP)(Me2bpy)][A], [Cu(xantphos)(Mebpy)][A] and [Cu(xantphos)(Me2bpy)][A] in which [A]− is [BF4]−, [PF6]−, [BPh4]− and [BArF4]− (Mebpy = 6-methyl-2,2′-bipyridine, Me2bpy = 6,6′-dimethyl-2,2′-bipyridine, POP = oxydi(2,1-phenylene)bis(diphenylphosphane), xantphos = (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane), [BArF4]− = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) are reported. Nine of the compounds have been characterised by single crystal X-ray crystallography, and the consequences of the different anions on the packing interactions in the solid state are discussed. The effects of the counterion on the photophysical properties of [Cu(POP)(N^N)][A] and [Cu(xantphos)(N^N)][A] (N^N = Mebpy and Me2bpy) have been investigated. In the solid-state emission spectra, the highest energy emission maxima are for [Cu(xantphos)(Mebpy)][BPh4] and [Cu(xantphos)(Me2bpy)][BPh4] (λemmax = 520 nm) whereas the lowest energy λemmax values occur for [Cu(POP)(Mebpy)][PF6] and [Cu(POP)(Mebpy)][BPh4] (565 nm and 563 nm, respectively). Photoluminescence quantum yields (PLQYs) are noticeably affected by the counterion; in the [Cu(xantphos)(Me2bpy)][A] series, solid-state PLQY values decrease from 62% for [PF6]−, to 44%, 35% and 27% for [BF4]−, [BPh4]− and [BArF4]−, respectively. This latter series of compounds was used as active electroluminescent materials on light-emitting electrochemical cells (LECs). The luminophores were mixed with ionic liquids (ILs) [EMIM][A] ([EMIM]+ = [1-ethyl-3-methylimidazolium]+) containing the same or different counterions than the copper(i) complex. LECs containing [Cu(xantphos)(Me2bpy)][BPh4] and [Cu(xantphos)(Me2bpy)][BArF4] failed to turn on under the LEC operating conditions, whereas those with the smaller [PF6]− or [BF4]− counterions had rapid turn-on times and exhibited maximum luminances of 173 and 137 cd m−2 and current efficiencies of 3.5 and 2.6 cd A−1, respectively, when the IL contained the same counterion as the luminophore. Mixing the counterions ([PF6]− and [BF4]−) of the active complex and the IL led to a reduction in all the figures of merit of the LECs. The choice of counterion in heteroleptic copper(i) luminophores for LECs has a critical effect on the photoluminescence quantum yields of the solid materials, and on the device figures-of-merit. |
| Databáze: | OpenAIRE |
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