2024-03-28T19:52:34Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1116232016-02-18T02:56:07Zcom_10261_52707com_10261_5col_10261_52708
2015-03-02T12:56:24Z
urn:hdl:10261/111623
CCC-pincer-NHC osmium complexes: New types of blue-green emissive neutral compounds for organic light-emitting devices (OLEDs)
Alabau, Roberto G.
Eguillor, Beatriz
Esler, Jim
Esteruelas, Miguel A.
Oliván, Montserrat
Oñate, Enrique
Tsai, Jui-Yi
Xia, Chuanjun
Ministerio de Economía y Competitividad (España)
European Commission
Diputación General de Aragón
Novel 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.
2015-03-02T12:56:24Z
2015-03-02T12:56:24Z
2014
2015-03-02T12:56:24Z
artículo
Organometallics 33(19): 5582-5596 (2014)
http://hdl.handle.net/10261/111623
10.1021/om500905t
http://dx.doi.org/10.13039/501100003329
http://dx.doi.org/10.13039/501100000780
eng
Sí
closedAccess
American Chemical Society