English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/111623
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

CCC-pincer-NHC osmium complexes: New types of blue-green emissive neutral compounds for organic light-emitting devices (OLEDs)

AutorAlabau, Roberto G. ; Eguillor, Beatriz ; Esler, Jim; Esteruelas, Miguel A. ; Oliván, Montserrat ; Oñate, Enrique ; Tsai, Jui-Yi; Xia, Chuanjun
Fecha de publicación2014
EditorAmerican Chemical Society
CitaciónOrganometallics 33(19): 5582-5596 (2014)
ResumenNovel homoleptic and heteroleptic NHC carbene containing bis(tridentate) osmium(II) complexes have been designed, synthesized, and characterized, and their photophysical properties have been studied. The complex OsH6(PiPr3)2 (1) reacts with the tetrafluoroborate salts of 1,3-bis(3-methylbenzimidazolium-1-yl)benzene and 1,3-bis(3-methylimidazolium-1-yl)benzene, in dimethylformamide, under reflux to afford the hydride-carbonyl derivatives [OsH(CNHCCarylCbenzimidazolium)(CO)(PiPr3)2]BF4 (2) and [OsH(CNHCCarylCimidazolium)(CO)(PiPr3)2]BF4 (3), as a result of the direct metalation of one of the NHC units of the salts, the activation of the C-H bond at the 6-position of the bridged aryl group, and metal carbonylation by solvent decarbonylation. In contrast to the BF4 salts, under the same conditions, the iodide salts of 1,3-bis(3-methylbenzimidazolium-1-yl)benzene, 1,3-bis(3-methylimidazolium-1-yl)benzene, and 1,3-bis(3-methylbenzimidazolium-1-yl)-5-trifluoromethylbenzene undergo direct metalation of both NHC units and C-H bond activation of the bridged aryl group at the 2-position to give the respective osmium(IV) dihydrides [OsH2(CNHCCarylCNHC)(PiPr3)2]I (4a-6a), which by deprotonation with KtBuO yield the osmium(II) monohydrides OsH(CNHCCarylCNHC)(PiPr3)2 (7-9). The reactions of 7 with 1,3-bis(3-methylbenzimidazolium-1-yl)benzene tetrafluoroborate and of 9 with 1,3-bis(3-methylbenzimidazolium-1-yl)-5-trifluoromethylbenzene tetrafluoroborate lead to the homoleptic derivatives Os(CNHCCarylCNHC)2 (10, 11), whereas the reactions of 9 with the tetrafluoroborate salts of 1,3-bis(3-methylbenzimidazolium-1-yl)benzene and 1,3-bis(3-methylimidazolium-1-yl)benzene generate heteroleptic Os(CNHCCarylCNHC)(CNHCCaryl'CNHC) (12) and Os(CNHCCaryl'CNHC)(CNHC'CarylCNHC') (13). Treatment of 7 with 3,5-bis(3-methylbenzimidazolium-1-yl)-2,6-dimethylpyridine tetrafluoroborate affords the salt [Os(CNHCCarylCNHC)(CNHCCaryl'CNHC)]BF4 (14), with Caryl' being a pyridinium group. Its deprotonation generates the neutral heteroleptic derivative Os(CNHCCarylCNHC)(CNHCCaryl'CNHC) (15). Complexes 10-13 and 15 are emissive in the blue-green spectral region with high quantum yields in the solid state, which reach 0.62 for 11. OLEDs using this compound as an emitting material show blue emission (CIE coordinates: (0.14, 0.26)). The brightness of the device reaches 10000 cd/m2 at 9.5 V. The maximum external quantum efficiency (EQE) was 19.2% at 1000 cd/m2.
Identificadoresdoi: 10.1021/om500905t
issn: 0276-7333
e-issn: 1520-6041
Aparece en las colecciones: (ISQCH) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
accesoRestringido.pdf15,38 kBAdobe PDFVista previa
Mostrar el registro completo

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.