Influence of Substituents on the Energy and Nature of the Lowest Excited States of Heteroleptic Phosphorescent Ir(III) Complexes: A Joint Theoretical and Experimental Study
Avilov, I.V.; Minoofar, P.; Cornil, Jérômeet al.
2007 • In Journal of the American Chemical Society, 129 (26), p. 8247-8258
[en] A series of Ir(III)-based heteroleptic complexes with phenylpyridine (ppy) and 2-(5-phenyl-4H-[1,2,4]triazol-3-yl)-pyridine (ptpy) derivatives as coordinating ligands has been characterized by a number of experimental and theoretical techniques. Density functional theory (DFT) calculations were able to reproduce and rationalize the experimental redox and excited-states properties of the Ir complexes under study. The introduction of fluorine and trifluoromethyl substituents is found not only to modulate the emission energy but also often to change the ordering of the lowest excited triplet states and hence their localization. The lowest triplet states are best characterized as local excitations of one of the chromophoric ligands (ppy or ptpy). The admixture of metal-to-ligand charge-transfer (MLCT) and ligand-to-ligand charge-transfer (LLCT) character is small and strongly depends on the nature of the excited state; their role is, however, primordial in defining the radiative decay rate of the complexes. The extent of charge-transfer contributions depends on the energy gaps between the relevant molecular orbitals, which can be modified by the substitution pattern.
Influence of Substituents on the Energy and Nature of the Lowest Excited States of Heteroleptic Phosphorescent Ir(III) Complexes: A Joint Theoretical and Experimental Study
Publication date :
04 July 2007
Journal title :
Journal of the American Chemical Society
ISSN :
0002-7863
Publisher :
American Chemical Society, United States - District of Columbia
Volume :
129
Issue :
26
Pages :
8247-8258
Peer reviewed :
Peer Reviewed verified by ORBi
Research unit :
S817 - Chimie des matériaux nouveaux
Research institute :
R400 - Institut de Recherche en Science et Ingénierie des Matériaux
Kwon, T.-H.; Cho, H. S.; Kim, M. K.; Kim, J.-Wh.; Kim, J.-J.; Lee, K. H.; Park, S. J.; Shin, I.-S.; Kim, H.; Shin, D. M.; Chung, Y. K.; Hong, J.-I. Organometallics 2005, 24, 1578-1585.
Mak, Ch. S. K.; Hayer, A.; Pascu, S. I.; Watkins, S. E.; Holmes, A. B.; Köhler, A.; Friend, R. H. Chem. Commun. 2005, 4708-4710.
Li, J.; Djurovich, P. I.; Alleyne, B. D.; Yousufuddin, M.; Ho, N. N.; Thomas, J. C.; Peters, J. C.; Bau, R.; Thompson, M. E. Inorg. Chem. 2005, 44, 1713-1727.
Colombo, M. G.; Hauser, A.; Güdel, H. U. Inorg. Chem. 1993, 32, 3081-3087.
Colombo, M. G.; Brunold, T. C.; Hauser, A.; Güdel, H. U.; Förtsch, M.; Bürgi, H.-B. Inorg. Chem. 1994, 33, 545-550.
Colombo, M. G.; Hauser, A.; Güdel, H. U. In Topics in Current Chemistry; Yersin, H., Ed.; Electronic and Vibronic Spectra of Transition Metal Complexes I; Springer: Berlin/Heidelberg, 1994; Vol. 171, pp 143-171.
Polson, M.; Fracasso, S.; Bertolasi, V.; Ravaglia, M.; Scandola, F. Inorg. Chem. 2004, 43, 1950-1956.
Lamansky, S.; Djurovich, P.; Murphy, D.; Abdel-Razzaq, F.; Kwong, R.; Tsyba, I.; Bortz, M.; Mui, B.; Bau, R.; Thompson, M. E. Inorg. Chem. 2001, 40, 1704-1711.
Tamayo, A. B.; Garon, S.; Sajoto, T.; Djurovich, P. I.; Tsyba, I. M.; Bau, R.; Thompson, M. E. Inorg. Chem. 2005, 44, 8723-8732.
Hay, P. J. J. Phys. Chem. A 2002, 106, 1634-1641.
Pohl, R.; Anzenbacher, P., Jr. Org. Lett. 2003, 5, 2769-2772.
Montes, V. A.; Pohl, R.; Li, G.; Shinar, J.; Anzenbacher, P., Jr. Adv. Mater. 2004, 16, 2001-2003.
Becke, A. D. J. Chem. Phys. 1993, 98, 5648-5652.
Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B 1988, 37, 785-789.
Hay, P. J.; Wadt, W. R. J. Chem. Phys. 1985, 82, 299-310.
Casida, M. E.; Jamorski, C.; Casida, K. C.; Salahub, D. R. J. Chem. Phys. 1998, 108, 4439-4449.
Stratmann, R. E.; Scuseria, G. E.; Frisch, M. J. J. Chem. Phys. 1998, 109, 8218-8224.
Orselli, E.; Kottas, G. S.; Konradsson, A.; Coppo, P.; Fröhlich, R.; De Cola, L.; van Dijken, A.; Buechel, M.; Boerner, H., submitted.
Dreuw, A.; Head-Gordon, M. Chem. Rev. 2005, 105, 4009-4037.
Martin, R. L. J. Chem. Phys. 2003, 118, 4775-4777.
King, K. A.; Watts, R. J. J. Am. Chem. Soc. 1987, 109, 1589-1590.
Wilde, A. P.; King, K. A.; Watts, R. J. J. Phys. Chem. 1991, 95, 629-634.
Beljonne, D.; Cornil, J.; Brédas, J. L.; Friend, R. H.; Janssen, R. A. J. J. Am. Chem. Soc. 1996, 118, 6453-6461.
Beljonne, D.; Cornil, J.; Brédas, J. L.; Friend, R. H. Synth. Met. 1996, 76, 61-65.
Beljonne, D.; Wittmann, H. F.; Köhler, A.; Graham, S.; Younus, M.; Lewis, J.; Raithby, P. R.; Khan, M. S.; Friend, R. H.; Brédas, J. L. J. Chem. Phys. 1996, 105, 3868-3877.
Dos Santos, D. A.; Beljonne, D.; Cornil, J.; Brédas, J. L. Chem. Phys. 1998, 227, 1-10.
Avilov, I.; Marsal, P.; Brédas, J. L.; Beljonne, D. Adv. Mater. 2004, 16, 1624-1629.