Substituted ꢀ-Diketonates for Heteroleptic Ir(III) Complexes
this series, Ir(III) cores are particularly promising because of
their favorable short phosphorescent lifetimes, well-suited energy
levels, stability and environmental inertness.2q,8g,9a The decora-
tion with heteroaromatic cyclometalating C∧N ligands was also
found to give rise in the variability of the emission color of
Ir(III) complexes.2a,b,8g Generally, cyclometalating ligands that
contain electron-withdrawing functions (e.g., fluorine or nitrile
substituents) serve to tune the emission color of the resulting
Ir(III) complexes toward higher energies and thus to the blue,12
whereas electron-pushing functions (e.g., alkyl substituents or
aromatic rings that contribute to an increased π-conjugation)
will result in emission color tuning toward lower energies and
thus to the red.2a,b,8g,13 While in homoleptic Ir(III) complexes
all cyclometalating ligands influences the electro-optical proper-
ties such as emission color, oxidation potentials, lifetimes, and
quantum yields, to name a few, in heteroleptic Ir(III) complexes
the ancillary ligands usually have almost no impact on the
electro-optical properties of the Ir(III) complexes2a,b,i,p,8g even
though some other examples are known from literature.2i,p
Prominent ancillary ligands are acetylacetone (acac) and its
derivatives.14 Recently, the functionalization of acetylacetones
gave increase to the functionality of the Ir(III) complexes
without disturbing the electro-optical properties of the metal
(4) (a) Cho, J.-Y.; Domercq, B.; Barlow, S.; Suponitsky, K. Y.; Li, J.;
Timofeeva, T. V.; Jones, S. C.; Hayden, L. E.; Kimyonok, A.; South, C. R.;
Weck, M.; Kippelen, B.; Marder, S. R. Organometallics 2007, 26, 4816–4829.
(b) Cocchi, M.; Virgili, D.; Fattori, V.; Rochester, D. L.; Williams, J. A. G.
AdV. Funct. Mater. 2007, 17, 285–289. (c) Wong, W.-Y.; He, Z.; So, S.-K.;
Tong, K.-L.; Lin, Z. Organometallics 2005, 24, 4079–4082. (d) Lu, W.; Mi,
B.-X.; Chan, M. C. W.; Hui, Z.; Che, C.-M.; Zhu, N.; Lee, S.-T. J. Am. Chem.
Soc. 2004, 126, 4958–4971. (e) Chan, S.-C.; Chan, M. C. W.; Wang, Y.; Che,
C.-M.; Cheung, K.-K.; Zhu, N. Chem. Eur. J. 2001, 7, 4180–4190. (f) Yang,
X.; Wang, Z.; Madakuni, S.; Li, J.; Jabbour, G. E. AdV. Mater. 2008, 20, 2405–
2409. (h) Ma, B.; Djurovich, P. I.; Garon, S.; Alleyne, B.; Thompson, M. E.
AdV. Funct. Mater. 2006, 16, 2438–2446.
(5) (a) Gao, F.; Wang, Y.; Zhang, J.; Shi, D.; Wang, M.; Humphry-Baker,
R.; Wang, P.; Zakeeruddin, S. M.; Gra¨tzel, M. Chem. Commun. 2008, 23, 2635–
2637. (b) Kuang, D.; Klein, C.; Ito, S.; Moser, J.-E.; Humphry-Baker, R.;
Zakeeruddin, S. M.; Gra¨tzel, M. AdV. Funct. Mater. 2007, 17, 154–160. (c) Kohle,
O.; Gra¨tzel, M.; Meyer, A. F.; Meyer, T. B. AdV. Mater. 1997, 9, 904–906. (d)
Reynal, A.; Forneli, A.; Martinez-Ferrero, E.; Sanchez-Diaz, A.; Vidal-Ferran,
A.; Palomares, E. Eur. J. Inorg. Chem. 2008, 12, 1955–1958. (e) Chen, C.-Y.;
Wu, S.-J.; Li, J.-Y.; Wu, C.-G.; Chen, J.-G.; Ho, K.-C. AdV. Mater. 2007, 19,
3888–3891. (f) Chen, K.-S.; Liu, W.-H.; Wang, Y.-H.; Lai, C.-H.; Chou, P.-T.;
Lee, G.-H.; Chen, K.; Chen, H.-Y.; Chi, Y.; Tung, F.-C. AdV. Funct. Mater.
2007, 17, 2964–2974. (g) Cho, T. J.; Shreiner, C. D.; Hwang, S.-H.; Moorefield,
C. N.; Courneya, B.; Godinez, L. A.; Manriquez, J.; Jeong, K.-U.; Cheng,
S. Z. D.; Newkome, G. R. Chem. Commun. 2007, 43, 4456–4458. (h) Wadman,
S. H.; Kroon, J. M.; Bakker, K.; Lutz, M.; Spek, A. L.; van Klink, G. P. M.;
van Koten, G. Chem. Commun. 2007, 19, 1907–1909. (i) Jang, S.-R.; Lee, C.;
Choi, H.; Ko, J. J.; Lee, J.; Vittal, R.; Kim, K.-J. Chem. Mater. 2006, 18, 5604–
5608.
(1) (a) Welter, S.; Brunner, K.; Hofstraat, J. W.; De Cola, L. Nature 2003,
421, 54–57. (b) Zhao, W.; Liu, C.-Y.; Wang, Q.; White, J. M.; Bard, A. J. Chem.
Mater. 2005, 17, 6403–6406. (c) Bolink, H. J.; Cappelli, L.; Coronado, E.;
Gra¨tzel, M.; Nazeeruddin, M. K. J. Am. Chem. Soc. 2006, 128, 46–47. (d) Tung,
Y.-L.; Chen, L.-S.; Chi, Y.; Chou, P.-T.; Cheng, Y.-M.; Li, E. Y.; Lee, G.-H.;
Shu, C.-F.; Wu, F.-I.; Carty, A. J. AdV. Funct. Mater. 2006, 16, 1615–1626. (e)
Rudmann, H.; Shimada, S.; Rubner, M. F. J. Am. Chem. Soc. 2002, 124, 4918–
4921. (f) Bernards, D. A.; Slinker, J. D.; Malliaras, G. G.; Flores-Torres, S.;
Abruna, H. D. Appl. Phys. Lett. 2004, 84, 4980–4982.
(6) (a) Tolosa, L.; Gryczynski, I.; Eichhorn, L. R.; Dattelbaum, J. D.;
Castellano, F. N.; Rao, G.; Lakowicz, J. R. Anal. Biochem. 1999, 267, 114–
120. (b) Huber, C.; Werner, T.; Krause, C.; Klimant, I.; Wolfbeis, O. S. Anal.
Chim. Acta 1998, 364, 143–151. (c) Borisov, S. M.; Krause, C.; Arain, S.;
Wolfbeis, O. S. AdV. Mater. 2006, 18, 1511–1516. (d) Borisov, S. M.;
Vasylevska, A. S.; Krause, C.; Wolfbeis, O. S. AdV. Funct. Mater. 2006, 16,
1536–1542. (e) Stich, M. I. J.; Nagl, S.; Wolfbeis, O. S.; Henne, U.; Schaeferling,
M. AdV. Funct. Mater. 2008, 18, 1399–1406. (f) Clarke, Y.; Xu, W.; Demas,
J. N.; DeGraff, B. A. Anal. Chem. 2000, 72, 3468–3475. (g) Thomas, S. W., III;
Venkatesan, K.; Mueller, P.; Swager, T. M. J. Am. Chem. Soc. 2006, 128, 16641–
16648.
(2) (a) Lamansky, S.; Djurovich, P.; Thompson, M. E. J. Am. Chem. Soc.
2001, 123, 4304–4312. (b) Lamansky, S.; Djurovich, P.; Murphy, D.; Abdel-
Razzaq, F.; Kwong, R.; Tsyba, I.; Bortz, M.; Mmui, B.; Bau, R.; Thompson,
M. E. Inorg. Chem. 2001, 40, 1704–1711. (c) Chang, C.-F.; Cheng, Y.-M.; Chi,
Y.; Chiu, Y.-C.; Lin, C.-C.; Lee, G.-H.; Chou, P.-T.; Chen, C.-C.; Chang, C.-
H.; Wu, C.-C. Angew. Chem., Int. Ed. 2008, 47, 4542–4545. (d) Kang, D. M.;
Kang, J.-W.; Park, J. W.; Jung, S. O.; Lee, S.-H.; Park, H.-D.; Kim, Y.-H.;
Shin, S. C.; Kim, J.-J.; Kwon, S.-K. AdV. Mater. 2008, 20, 2003–2007. (e)
Rehmann, N.; Ulbricht, C.; Koehnen, A.; Zacharias, P.; Gather, M. C.; Hertel,
D.; Holder, E.; Meerholz, K.; Schubert, U. S. AdV. Mater. 2008, 20, 129–133.
(f) Ragni, R.; Plummer, E. A.; Brunner, K.; Hofstraat, J. W.; Babudri, F.; Farinola,
G. M.; Naso, F.; De Cola, L. J. Mater. Chem. 2006, 16, 1161–1170. (g) Bolink,
H. J.; Coronado, E.; Garcia Santamaria, S.; Sessolo, M.; Evans, N.; Klein, C.;
Baranoff, E.; Kalyanasundaram, K.; Gra¨tzel, M.; Nazeeruddin, M. K. Chem.
Commun. 2007, 31, 3276–3278. (h) You, Y.; An, C.-G.; Kim, J.-J.; Park, S. Y.
J. Org. Chem. 2007, 72, 6241–6246. (i) Chen, L.; You, H.; Yang, C.; Ma, D.;
Qin, J. Chem. Commun. 2007, 13, 1352–1354. (j) Lo, S.-C.; Richards, G. J.;
Markham, J. P. J.; Namdas, E. B.; Sharma, S.; Burn, P. L.; Samuel, I. D. W.
AdV. Funct. Mater. 2005, 15, 1451–1458. (k) Ostrowski, J. C.; Robinson, M. R.;
Heeger, A. J.; Bazan, G. C. Chem. Commun. 2002, 7, 784–785. (l) Evans, N. R.;
Sudha, D. L.; Mak, C. S. K.; Watkins, S. E.; Pascu, S. I.; Ko¨hler, A.; Friend,
R. H.; Williams, C. K.; Holmes, A. B. J. Am. Chem. Soc. 2006, 128, 6647–56.
(m) Williams, E. L.; Li, J.; Jabbour, G. E. Appl. Phys. Lett. 2006, 89, 083506/
1–083506/3. (n) Tavasli, M.; Bettington, S.; Perepichka, I. F.; Batsanov, A. S.;
Bryce, M. R.; Rothe, C.; Monkman, A. P. Eur. J. Inorg. Chem. 2007, 30, 4808–
4814. (o) Slinker, J. D.; Koh, C. Y.; Malliaras, G. G.; Lowry, M. S.; Bernhard,
S. Appl. Phys. Lett. 2005, 86, 173506/1–173506/3. (p) You, Y.; Park, S. Y. J. Am.
Chem. Soc. 2005, 127, 12438–12439. (q) Ko¨hler, A.; Wilson, J. S.; Friend, R. H.
AdV. Mater. 2002, 14, 701–707. (r) Ho, C.-L.; Wong, W.-Y.; Zhou, G.-J.; Yao,
B.; Xie, Z.; Wang, L. AdV. Funct. Mater. 2007, 17, 2925–2936. (s) Breu, J.;
Stoessel, P.; Schrader, S.; Starukhin, A.; Finkenzeller, W. J.; Yersin, H. Chem.
Mater. 2005, 17, 1745–1752. (t) Wu, H.; Zou, J.; Liu, F.; Wang, L.;
Mikhailovsky, A.; Bazan, G. C.; Yang, W.; Cao, Y. AdV. Mater. 2008, 20, 696–
702. (u) Finkenzeller, W. J.; Hofbeck, T.; Thompson, M. E.; Yersin, H. Inorg.
Chem. 2007, 46, 5076–5083. (v) Lo, S.-C.; Namdas, E. B.; Burn, P. L.; Samuel,
I. D. W. Macromolecules 2003, 36, 9721–9730. (w) Yang, X.-H.; Wu, F.-I.;
Neher, D.; Chien, C.-H.; Shu, C.-F. Chem. Mater. 2008, 20, 1629–1635. (x)
Wu, F.-I.; Yang, X.-H.; Neher, D.; Dodda, R.; Tseng, Y.-H.; Shu, C.-F. AdV.
Funct. Mater. 2007, 17, 1085–1092. (y) Yang, X.-H.; Jaiser, F.; Stiller, B.; Neher,
D.; Galbrecht, F.; Scherf, U. AdV. Funct. Mater. 2006, 16, 2156–2162. (z) Yang,
X.-H.; Jaiser, F.; Klinger, S.; Neher, D. Appl. Phys. Lett. 2006, 88, 021107/1–
021107/3.
(7) Knapton, D.; Burnworth, M.; Rowan, S. J.; Weder, C. Angew. Chem.,
Int. Ed. 2006, 45, 5825–5829.
(8) (a) Polo, A. S.; Itokazu, M. K.; Murakami Iha, N. Y. Coord. Chem. ReV.
2004, 248, 1343–1361. (b) Endicott, J. F.; Schlegel, H. B.; Uddin, M. J.;
Seniveratne, D. S. Coord. Chem. ReV. 2002, 229, 95–106. (c) Chi, Y.; Chou,
P.-T. Chem. Soc. ReV. 2007, 36, 1421–1431. (d) De Cola, L.; Belser, P.; Von
Zelewsky, A.; Voegtle, F. Inorg. Chim. Acta 2007, 360, 775–784. (e) Marin,
V.; Holder, E.; Hoogenboom, R.; Schubert, U. S. Chem. Soc. ReV. 2007, 36,
618–635. (f) Serroni, S.; Campagna, S.; Puntoriero, F.; Di Pietro, C.; McClena-
ghan, N. D.; Loiseau, F. Chem. Soc. ReV. 2001, 30, 367–375. (g) Holder, E.;
Langeveld, B. M. W.; Schubert, U. S. AdV. Mater. 2005, 17, 1109–1121.
(9) (a) Baldo, M. A.; Thompson, M. E.; Forrest, S. R. Nature 2000, 403,
750–753. (b) Dixon, I. M.; Collin, J.-P.; Sauvage, J.-P.; Flamigni, L.; Encinas,
S.; Barigelletti, F. Chem. Soc. ReV. 2000, 29, 385–391. (c) Lowry, M. S.;
Bernhard, S. Chem. Eur. J. 2006, 12, 7970–7977. (d) Haldi, A.; Kimyonok, A.;
Domercq, B.; Hayden, L. E.; Jones, S. C.; Marder, S. R.; Weck, M.; Kippelen,
B. AdV. Funct. Mater. 2008, 18, 3056–3062. (e) Kimyonok, A.; Domercq, B.;
Haldi, A.; Cho, J.-Y.; Carlise, J. R.; Wang, X.-Y.; Hayden, L. E.; Jones, S. C.;
Barlow, S.; Marder, S. R.; Kippelen, B.; Weck, M. Chem. Mater. 2007, 19,
5602–5608. (f) Wang, X.-Y.; Kimyonok, A.; Weck, M. Chem. Commun. 2006,
37, 3933–3935. (g) Wang, X.-Y.; Prabhu, R. N.; Schmehl, R. H.; Weck, M.
Macromolecules 2006, 39, 3140–3146. (h) Carlise, J. R.; Wang, X.-Y.; Weck,
M. Macromolecules 2005, 38, 9000–9008.
(10) (a) Baldo, M. A.; O’Brien, D. F.; You, Y.; Shoustikov, A.; Sibley, S.;
Thompson, M. E.; Forrest, S. R. Nature 1998, 395, 151–154. (b) Hissler, M.;
McGarrah, J. E.; Connick, W. B.; Geiger, D. K.; Cummings, S. D.; Eisenberg,
R. Coord. Chem. ReV. 2000, 208, 115–137. (c) Silverman, E. E.; Cardolaccia,
T.; Zhao, X.; Kim, K.-Y.; Haskins-Glusac, K.; Schanze, K. S. Coord. Chem.
ReV. 2005, 249, 1491–1500. (d) Venkatesan, K.; Kouwer, P. H. J.; Yagi, S.;
Mueller, P.; Swager, T. M. J. Mater. Chem. 2008, 18, 400–407.
(11) Barbieri, A.; Accorsi, G.; Armaroli, N. Chem. Commun. 2008, 19, 2185–
2193.
(12) Yang, C.-H.; Cheng, Y.-M.; Chi, Y.; Hsu, C.-J.; Fang, F.-C.; Wong,
K.-T.; Chou, P.-T.; Chang, C.-H.; Tsai, M.-H.; Wu, C.-C. Angew. Chem., Int.
Ed. 2007, 46, 2418–2421.
(3) (a) Chien, C.-H.; Liao, S.-F.; Wu, C.-H.; Shu, C.-F.; Chang, S.-Y.; Chi,
Y.; Chou, P.-T.; Lai, C.-H. AdV. Funct. Mater. 2008, 18, 1430–1439. (b) Chou,
P.-T.; Chi, Y. Chem. Eur. J. 2007, 13, 380–395. (c) Tung, Y.-L.; Lee, S.-W.;
Chi, Y.; Tao, Y.-T.; Chien, C.-H.; Cheng, Y.-M.; Chou, P.-T.; Peng, S.-M.; Liu,
C.-S. J. Mater. Chem. 2005, 15, 460–464. (d) Carlson, B.; Phelan, G. D.;
Kaminsky, W.; Dalton, L.; Jiang, X.; Liu, S.; Jen, A. K. Y. J. Am. Chem. Soc.
2002, 124, 14162–14172.
(13) Zhou, G.; Wong, W.-Y.; Yao, B.; Xie, Z.; Wang, L. Angew. Chem.,
Int. Ed. 2007, 46, 1149–1151.
(14) (a) Liu, Z. W.; Guan, M.; Bian, Z. Q.; Nie, D. B.; Gong, Z. L.; Li,
Z. B.; Huang, C. H. AdV. Funct. Mater. 2006, 16, 1441–1448. (b) Bronstein,
H. A.; Finlayson, C. E.; Kirov, K. R.; Friend, R. H.; Williams, C. K.
Organometallics 2008, 27, 2980–2989.
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