Sublimation not an innocent technique: a case of bis-cyclometalated iridium emitter for OLED.
Isomerization of a neutral bis-cyclometalated iridium(III) complex has been observed for the first time during the preparation of vacuum-processed organic light-emitting devices (OLEDs) and reproduced in solution. Isolation of the isomer revealed a cis organization of the two pyridine rings of the cyclometalating ligands. Photophysical studies show very similar emission properties of the two isomers. However, due to in situ isomerization, it is only possible to prepare vacuum-processed OLED devices having a mixture of isomers.
Baranoff
Etienne
E
Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland.
Suàrez
Stéphane
S
Bugnon
Philippe
P
Barolo
Claudia
C
Buscaino
Roberto
R
Scopelliti
Rosario
R
Zuppiroli
Libero
L
Graetzel
Michael
M
Nazeeruddin
Md K
MK