[1] [1] Baldo M A, O’Brien D F, Shoustikov Y A, et al. Nature., 1998, 395: 151.

[3] [3] Lamansky S, Djurovich P, Murphy D, et al. Inorg Chem., 2001, 40(7): 1704.

[4] [4] Fei T, Gu X, Zhang M, et al. Synth. Metals, 2009, 159(1): 113.

[5] [5] Lamansky S, Djurovich P, Murphy D, et al. J. Am. Chem. Soc., 2001, 123(18): 4304.

[6] [6] Baldo M A, Lamansky S, Burrows P E, et a1. App1. Phys. Lett., 1999, 75(1): 4.

[7] [7] Takashi K, Etsuko I, Shiki Y, et al. Chemical Physics Letters, 2006, 424(4-6): 353.

[8] [8] Adachi C, Baldo M A, Forrest S R, et al. Appl. Phys. Lett., 2000, 77: 6904.

[9] [9] Nonoyama M Bull. Chem. Soc. Jpn., 1974, 47(3):767.

[10] [10] Ahn S Y, Lee H S, Seo J, et al. Thin Solid Films, 2009, 517(14): 4111.

[11] [11] Park Y H, Kim Y S, Curr. Appl. Phys., 2007, 7: 500.

[12] [12] You Y, Kim K S, Ahn T K, et al. J. Phys. Chem. C., 2007, 111: 4052.

[13] [13] Nazeeruddin M K, Humphry-Baker R. J. Am. Chem. Soc., 2003, 125: 8790.

[14] [14] Paolo C, Edward A Plummer. Chem. Commun., 2004, (26): 1774.

[15] [15] Xu B S, Xu H X, Cheng L Q, et al. Organic Electron., 2008, 9: 267.

[16] [16] Xu B S, Xu H X, Fang X H, et al. Organic Electron., 2008, 9: 906.

[17] [17] Wu L L, Sun I W, Yang C H. Polyhedron, 2007, 26: 2679.

[18] [18] Tamayo A B, Alleyne B D, Djurovich P I, et al. J. Am. Chem. Soc., 2003, 125: 7377.