TY - JOUR
T1 - Structural, electronic and optical properties of multifunctional iridium(iii) and platinum(ii) metallophosphors for organic light-emitting diodes
AU - Ran, Xueqin
AU - Feng, Jikang
AU - WONG, Wai Yeung
AU - Ren, Aimin
AU - Zhou, Guijiang
AU - Sun, Chiachung
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/10
Y1 - 2012/10
N2 - An elaborated theoretical investigation on the optical and electronic properties of three fluorene-based platinum(II) and iridium(III) cyclometalated complexes Pt-a, Ir-a and Ir-b is reported. The geometric and electronic structures of the complexes in the ground state are studied with density functional theory and Hartree Fock approaches, while the lowest triplet excited states are optimized by singles configuration interaction (CIS) methods. At the time-dependent density functional theory (TD-DFT) level, molecular absorption and emission properties were calculated on the basis of optimized ground- and excited-state geometries, respectively. The computational results show that the appearance of triphenylamino (TPA) moiety at the 9-position of fluorene ring favors the hole-creation and leads to red-shifts of absorption and emission spectra. Moreover, Pt-a and Ir-b are nice hole-transporting materials whereas Ir-a has good charge-transfer balance, which render them useful for the realization of efficient OLEDs (Organic Light-Emitting Diodes). Obvious metal-to-ligand charge transfer (MLCT) occurs during low energy transitions, which is the decisive factor for the occurrence of spin-forbidden electron transition. The introduction of triphenylamino (TPA) units improves hole-creation ability and the extent of conjugation, leading to red-shifts in absorption and emission spectra.
AB - An elaborated theoretical investigation on the optical and electronic properties of three fluorene-based platinum(II) and iridium(III) cyclometalated complexes Pt-a, Ir-a and Ir-b is reported. The geometric and electronic structures of the complexes in the ground state are studied with density functional theory and Hartree Fock approaches, while the lowest triplet excited states are optimized by singles configuration interaction (CIS) methods. At the time-dependent density functional theory (TD-DFT) level, molecular absorption and emission properties were calculated on the basis of optimized ground- and excited-state geometries, respectively. The computational results show that the appearance of triphenylamino (TPA) moiety at the 9-position of fluorene ring favors the hole-creation and leads to red-shifts of absorption and emission spectra. Moreover, Pt-a and Ir-b are nice hole-transporting materials whereas Ir-a has good charge-transfer balance, which render them useful for the realization of efficient OLEDs (Organic Light-Emitting Diodes). Obvious metal-to-ligand charge transfer (MLCT) occurs during low energy transitions, which is the decisive factor for the occurrence of spin-forbidden electron transition. The introduction of triphenylamino (TPA) units improves hole-creation ability and the extent of conjugation, leading to red-shifts in absorption and emission spectra.
KW - fluorene-based platinum(II) and iridium(III) cyclometalated complexes
KW - intraligand
KW - metal-to-ligand charge transfer
KW - optical and electronic properties
UR - http://www.scopus.com/inward/record.url?scp=84867773662&partnerID=8YFLogxK
U2 - 10.1002/cjoc.201200273
DO - 10.1002/cjoc.201200273
M3 - Journal article
AN - SCOPUS:84867773662
SN - 1001-604X
VL - 30
SP - 2431
EP - 2439
JO - Chinese Journal of Chemistry
JF - Chinese Journal of Chemistry
IS - 10
ER -