2024-03-29T02:09:10Zhttps://riubu.ubu.es/oai/requestoai:riubu.ubu.es:10259/49392021-11-10T09:38:18Zcom_10259_3844com_10259_5086com_10259_2604col_10259_3845
Highly stable and efficient light-emitting electrochemical cells based on cationic iridium complexes bearing arylazole ancillary ligands
Martínez Alonso, Marta
Cerdá, Jesús .
Momblona, Cristina .
Pertegás, Antonio .
Junquera Hernández, José M. .
Heras, Aránzazu
Rodríguez, Ana M. .
Espino Ordóñez, Gustavo
Bolink, Henk .
Ortí, Enrique .
Química analítica
Chemistry, Analytic
A series of bis-cyclometalated iridium(III)
complexes of general formula [Ir(ppy)2(N∧N)][PF6] (ppy−
= 2-phenylpyridinate; N∧N = 2-(1H-imidazol-2-yl)pyridine
(1), 2-(2-pyridyl)benzimidazole (2), 1-methyl-2-pyridin-2-yl-
1H-benzimidazole (3), 2-(4′-thiazolyl)benzimidazole (4), 1-
methyl-2-(4′-thiazolyl)benzimidazole (5)) is reported, and
their use as electroluminescent materials in light-emitting
electrochemical cell (LEC) devices is investigated. [2][PF6]
and [3][PF6] are orange emitters with intense unstructured
emission around 590 nm in acetonitrile solution. [1][PF6],
[4][PF6], and [5][PF6] are green weak emitters with
structured emission bands peaking around 500 nm. The
different photophysical properties are due to the effect that the
chemical structure of the ancillary ligand has on the nature of the emitting triplet state. Whereas the benzimidazole unit stabilizes
the LUMO and gives rise to a 3MLCT/3LLCT emitting triplet in [2][PF6] and [3][PF6], the presence of the thiazolyl ring
produces the opposite effect in [4][PF6] and [5][PF6] and the emitting state has a predominant 3LC character. Complexes with
3MLCT/3LLCT emitting triplets give rise to LEC devices with luminance values 1 order higher than those of complexes with
3LC emitting states. Protecting the imidazole N−H bond with a methyl group, as in complexes [3][PF6] and [5][PF6], shows
that the emissive properties become more stable. [3][PF6] leads to outstanding LECs with simultaneously high luminance (904
cd m−2), efficiency (9.15 cd A−1), and stability (lifetime over 2500 h).
Spanish Ministry of Economy and
Competitiveness (MINECO) of Spain (projects CTQ2014-
58812-C2-1-R, MAT2014-55200, CTQ2014-55583-R,
CTQ2014-61914-EXP, CTQ2015-71955-REDT, CTQ2015-
70371-REDT, CTQ2015-71154-P, and Unidad de Excelencia
Marıá de Maeztu MDM-2015-0538), European Feder funds
(CTQ2015-71154-P), Obra Social “la Caixa” (OSLC-2012-
007), Junta de Castilla y León (BU033-U16), and Generalitat
Valenciana (Prometeo2016/135)
2018-09-12T11:40:07Z
2018-09-12T11:40:07Z
2017-09
info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
0020-1669
http://hdl.handle.net/10259/4939
10.1021/acs.inorgchem.7b01167
eng
Inorganic Chemistry. 2017, V. 56, n. 17, p. 10298–10310
https://doi.org/10.1021/acs.inorgchem.7b01167
info:eu-repo/grantAgreement/MINECO/CTQ2014-58812-C2-1-R
info:eu-repo/grantAgreement/MINECO/MAT2014-55200
info:eu-repo/grantAgreement/MINECO/CTQ2014-55583-R
info:eu-repo/grantAgreement/MINECO/CTQ2014-61914-EXP
info:eu-repo/grantAgreement/MINECO/CTQ2015-71955-REDT
info:eu-repo/grantAgreement/MINECO/CTQ2015-
70371-REDT
info:eu-repo/grantAgreement/MINECO/CTQ2015-71154-P
info:eu-repo/grantAgreement/MICINN/MDM-2015-0538
info:eu-repo/grantAgreement/FEDER/CTQ2015-71154-P
info:eu-repo/grantAgreement/FundaciónLaCaixa/OSLC-2012-007
info:eu-repo/grantAgreement/JCyL/BU033-U16
info:eu-repo/grantAgreement/GVA/Prometeo2016-135
info:eu-repo/semantics/openAccess
application/pdf
American Chemical Society