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Synthesis, properties and Light-Emitting Electrochemical Cell (LEEC) device fabrication of cationic Ir(III) complexes bearing electron-withdrawing groups on the cyclometallating ligands
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dc.contributor.author | Pal, Amlan Kumar | |
dc.contributor.author | Cordes, David Bradford | |
dc.contributor.author | Slawin, Alexandra Martha Zoya | |
dc.contributor.author | Momblona, Cristina | |
dc.contributor.author | Orti, Enrique | |
dc.contributor.author | Samuel, Ifor David William | |
dc.contributor.author | Bolink, Henk | |
dc.contributor.author | Zysman-Colman, Eli | |
dc.date.accessioned | 2016-10-25T09:30:18Z | |
dc.date.available | 2016-10-25T09:30:18Z | |
dc.date.issued | 2016-10-17 | |
dc.identifier.citation | Pal , A K , Cordes , D B , Slawin , A M Z , Momblona , C , Orti , E , Samuel , I D W , Bolink , H & Zysman-Colman , E 2016 , ' Synthesis, properties and Light-Emitting Electrochemical Cell (LEEC) device fabrication of cationic Ir(III) complexes bearing electron-withdrawing groups on the cyclometallating ligands ' , Inorganic Chemistry , vol. 55 , no. 20 , pp. 10361-10376 . https://doi.org/10.1021/acs.inorgchem.6b01602 | en |
dc.identifier.issn | 0020-1669 | |
dc.identifier.other | PURE: 245890091 | |
dc.identifier.other | PURE UUID: 5379c22d-4bd9-40f5-9f11-b2b505c239d2 | |
dc.identifier.other | Scopus: 84992065870 | |
dc.identifier.other | ORCID: /0000-0002-5366-9168/work/28023967 | |
dc.identifier.other | ORCID: /0000-0001-7183-6022/work/56639100 | |
dc.identifier.other | ORCID: /0000-0002-9527-6418/work/56861787 | |
dc.identifier.other | ORCID: /0000-0002-5677-5070/work/59464938 | |
dc.identifier.other | WOS: 000385785700051 | |
dc.identifier.uri | http://hdl.handle.net/10023/9696 | |
dc.description | The authors are grateful to the European Research Council (grant 321305), the EPSRC (EP/M02105X/1) and the University of St Andrews for financial support. C.M. thanks Ministry of Economy and Competitiveness (MINECO, Spain) for her predoctoral contract. | en |
dc.description.abstract | The structure-property relationship study of a series of cationic Ir(III) complexes in the form of [Ir(C^N)2(dtBubpy)]PF6 [where dtBubpy = 4,4′-ditert-butyl-2,2′- bipyridine and C^N = cyclometallating ligand bearing an electron-withdrawing group (EWG) at C4 of the phenyl substituent, i.e. -CF3 ( 1 ), -OCF3 ( 2 ), -SCF3 ( 3 ), -SO2CF3 ( 4 )] have been investigated. The physical and optoelectronic properties of the four complexes were comprehensively characterized, including by X-ray diffraction analysis. All the complexes exhibit quasi-reversible dtBubpy-based reductions from -1.29 V to -1.34 V (vs. SCE). The oxidation processes are likewise quasi-reversible (metal+C^N ligand) and are between 1.54- 1.72 V (vs. SCE). The relative oxidation potentials follow a general trend associated with the Hammett parameter (σ) of the EWGs. Surprisingly, complex 4 bearing the strongest EWG does not adhere to the expected Hammett behavior and was found to exhibit red-shifted absorption and emission maxima. Nevertheless, the concept of introducing EWGs was found to be generally useful in blue-shifting the emission maxima of the complexes (λem = 484-545 nm) compared to that of the prototype complex [Ir(ppy)2(dtBubpy)]PF6 (where ppy = 2- phenylpyridinato) (λem = 591 nm). The complexes were found to be bright emitters in solution at room temperature (ΦPL = 45-66%) with long excited-state lifetimes (τe = 1.14-4.28 μs). The photophysical properties along with Density Functional Theory (DFT) calculations suggest that the emission of these complexes originates from mixed contributions from ligand-centered (LC) transitions and mixed metal-to-ligand and ligand-to-ligand charge transfer (LLCT/MLCT) transitions, depending on the EWG. In complexes 1 , 3 and 4 the 3LC character is prominent over the mixed 3CT character while in complex 2 , the mixed 3CT character is much more pronounced, as demonstrated by DFT calculations and the observed positive solvatochromism effect. Due to the quasi-reversible nature of the oxidation and reduction waves, fabrication of light emitting electrochemical cells (LEECs) using these complexes as emitters was possible with the LEECs showing moderate efficiencies. | |
dc.language.iso | eng | |
dc.relation.ispartof | Inorganic Chemistry | en |
dc.rights | Copyright 2016 American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. | en |
dc.subject | QD Chemistry | en |
dc.subject | TP Chemical technology | en |
dc.subject | DAS | en |
dc.subject.lcc | QD | en |
dc.subject.lcc | TP | en |
dc.title | Synthesis, properties and Light-Emitting Electrochemical Cell (LEEC) device fabrication of cationic Ir(III) complexes bearing electron-withdrawing groups on the cyclometallating ligands | en |
dc.type | Journal article | en |
dc.contributor.sponsor | EPSRC | en |
dc.description.version | Publisher PDF | en |
dc.contributor.institution | University of St Andrews. School of Chemistry | en |
dc.contributor.institution | University of St Andrews. EaSTCHEM | en |
dc.contributor.institution | University of St Andrews. School of Physics and Astronomy | en |
dc.contributor.institution | University of St Andrews. Condensed Matter Physics | en |
dc.identifier.doi | https://doi.org/10.1021/acs.inorgchem.6b01602 | |
dc.description.status | Peer reviewed | en |
dc.identifier.grantnumber | EP/M02105X/1 | en |
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