兩類含imidazole的有機雜環化合物陽離子1-(2-pyridylmethyl)-3-(alkyl)benzimidazolium(2pm-Rb)和1-(2-pyridylmethyl)-3-(alkyl)imidazolium(2pm-Ri)與氯、溴、碘陰離子組合成的鹽類被合成出來。其中，R=2f、3f、4f、f5、2cl、3cl、4cl、4ome、b、m(見圖1)。

上序述鹽類化合物與[Ir(ppy)2(MeCN)2]NO3 (ppy=2-phenylpyridyl) 及Ag2O在甲醇下迴流一天，再經由陰離子交換，得到[Ir(ppy)2(N^C)]PF6共12個Ir(III)化合物(見圖2構造) ; N^C=2pm-4fb、2pm-3fb、2pm-2fb、2pm-f5b、2pm-4clb、2pm-3clb、2pm-2clb、2pm-4omeb、2pm-bb、2pmmb、2pm-bi、2pm-mi。上述錯合物的簡稱，以Ir’-R、Ir’-I-R為代號。

所有的錯合物，利用MS、IR、CV、UV-VIS、PL鑑定其性質 , 並且由X-ray data得到固態結構。
固態UV-Vis吸收峰位於330~500 nm較寬且normalized intensity約0.8比在CH2Cl2溶液中0.2強，造成的原因是由於分子內及分子間π—π stacking的影響。
而固態放光，拉電子基，會使分子內R 基團與鄰近ppy平面π—π stacking越強，穩定HOMO軌域導致固態放光藍移，例如Ir’-b(516 nm) Ir’-3f(506 nm)和Ir’-3cl (505 nm)。
;而分子間N^C配位基的pyridyl與其它N^C配位基的pyridyl π—π stacking會造成藍移，例如Ir’-b(516 nm)和Ir’-4f (507 nm)。
;另外分子間N^C ligand配位基的pyridyl與ppy的phenyl facial-to-edge π— π stacking以及ppy與ppy facial to facial π—π stacking作用，紅移。分子R基團與鄰近ppy平面 π—π stacking，藍移。總合的結果Ir’-2f(532nm)、Ir’-b(516nm)。

Two series of cations, 1-(2-pyridylmethyl)-3-(alkyl)benzimidazolium (2pm-Rb) and 1-(2-pyridylmethyl)-3-(alkyl)imidazolium (2pm-Ri) (R = 2f, 3f, 4f, f5, 2cl, 3cl, 4cl, 4ome, b, m (Figure 1)), with counter ions of Cl-, Br-, and I- were prepared. Reactions of the salts with [Ir(ppy)2(MeCN)2](NO3) and an excess amount of Ag2O in methanol under reflux overnight to produce twelve iridium complexes, [Ir(ppy)2(N^C)] (N^C = 2pm-4fb, 2pm-3fb, 2pm-2fb, 2pm-f5b, 2pm-4clb, 2pm-3clb, 2pm-2clb, 2pm-4omeb, 2pm-bb, 2pmmb, 2pm-bi, 2pm-mi), which were also abbreviated as Ir’-R and Ir’-I-R (Figure 2). All the iridium compounds have been characterized by MS, IR, UV-VIS, NMR, and PL. Further, the solid state structures of these complexes were also determined. Based on the UV-VIS normalized spectra, the intensity in a range of 330~500 nm for the complexes in the solid state is higher than that in solution (CH2Cl2) (0.6~0.8 vs. 0.1~0.2). The difference can be attributed into the presence of intra- and inter- molecular π-π stacking.
The electron-withdrawing substituents of the R moieties on the N^C ligand appear to strengthen the intramolecular facial-to-facial π—π stacking stackings via the plane of one R moiety to the neighboring ppy plane), and stabilize the HOMO, so that a clear blue shift was observed. Thus,λmax = 516 nm observed for Ir’-b is in contrast to 506 nm for Ir’-3f, and 505 nm for Ir’-3Cl. The intermolecular facial-to-facial π—π stacking stackings via the pyridyl plane of one N^C ligand to a sterically close pyridyl plane of another N^C ligand can also make a blue shift. Thus, λmax = 516 nm observed for Ir’-b is in contrast to 507 nm for Ir’-4f. The intermolecular facial-to-edge π—π stacking stackings via the pyridyl plane of one N^C ligand to a sterically close phenyl plane of another ppy ligand, the intermolecular facial-to-facial π—π stacking stackings via the pyridyl plane of one ppy ligand to a sterically close phenyl plane of another ppy ligand, and the intramolecular facial-to-facial π—π stacking stackings via the plane of one R moiety to the neighboring ppy plane can also make a red shift. Hence, λmax = 516 nm observed for Ir’-b is in contrast to 532 nm for Ir’-2f.

1.Lamansky, S.; Djurovich, P.; DrewMurphy, D.; Abdel-Razzaq, F.; Lee, H.-E.; Adachi, C.; Burrows, P. E.; Forrest, S. R.; Thompson, M.E., J. Am. Chem. Soc., 2001, 123, 4304.
2.King, K. A.; Spellane, P. J.; Watts, R. J., J. Am. Chem. Soc., 1985, 107, 1431.
3.DeRosa, M. C.; Hodgson, D. J.; Enright, G. D.; Dawson, B.; E. B. Evans, C. E. B.; Crutchley, R. J., J. Am. Chem. Soc., 2004, 126, 7619.
4.Tokito, S.; Iijima, T.; Tsuzuki, T.; Sato, F., Appl. Phys. Lett., 2003, 83, 2459.
5.Tang, C. W. and VanSlyke, S. A., Appl. Phys. Lett., 1987, 51, 913.
6.Tang, C. W.; VanSlyke; S. A. and Chen, C. H., J. Appl. Phys., 1989, 65, 3610.
7.吳麗嵐，苯基吡啶銥金屬及苯基仳唑銥金屬於有機發光元件的應用，95年成功大學化學所碩士論文
8.Baldo, M. A.; O’Brien, D. F.; You, Y.; Shoustikov, A.; Sibley, S.; Thompson, M. E.; Forrest, S. R., Nature, 1998, 395, 151
9.Thompson, M. E.; Shoustikov, A.; You, Y.; Sibley, S.; Baldo, M.; Koslov, V.; Burrows, E. P.; Forrest, S. R. MRS Abstract, G2.4, Spring Meeting, 1998.
10.O’Brien, D. F.; Baldo, M. A.; Thompson, M. E.; Forrest, S. R., Appl. Phys. Lett, 1999, 74, 442 .
11.Baldo, M. A.; O’Brien, D. F.; Thompson, M. E.; Forrest, S. R., Phys. Rev. B, 1999, 60, 14422.
12.Jiang, X; Liu, Y.; Song, X.; Zhu D., Synth. Met., 1997, 87, 175.
13.Pielichowski, J.; Chrzszcz, R.; Nizio, S.; Barta, P.; Sanetra, J., Synth. Met., 1998, 94, 123.
14.Hanai, N.; Sumitomo, M.; Yanag, H., Thin Solid Films, 1998, 331 ,106.
15.Vestweber, H.; Rieβ, W., Synth. Met., 1997, 91, 181.
16.Riel, H.; Brütting, W.; Bererlein, T.; Haskal, E.; Müller, P.; Riess, W., Synth. Met., 2000, 111, 303.
17.Zhilin, Z.; Xueyin, J.; Shaohong, X., Thin Solid Films, 2000, 363, 61.
18.Era, M.; Tsutsi, T.; Saito, S., Appl. Phys. Lett., 1995, 67, 2436.
19.Aminaka, E. I.; Tsutsui, T.; Saito, S., J. Appl. Phys., 1996, 79, 8808.
20.Era, M.; Tsutsi, T.; Takehara, K.; Isomura, K.; Taniguchi, H., Thin Solid Films, 2000, 363, 229.
21.Hung, L. S.; Tang, C. W.; Mason, M. G., Appl. Phys. Lett., 1997, 70, 152.
22.Staudigel, J.; Stöβel, M.; Steuber, F.; Blässing, J.; Simmerer, J., Synth. Met., 2000, 111, 69.
23.Fischer, E. O.; Maasböl, A., Angew. Chem. internut. Edit., 1964, 3, 580.
24.Richard R. Schrock, J. Am. Chem. Soc., 1974, 96, 6796.
25.李漢文,CHEMISTRY（THE CHINESE CHEM. SOC., TAIPEI）, 2005,63,491
26.Boehme, C.; Frenking, G., Organometallics, 1998, 17, 5801.
27.Lee, M.-T.; Hu, C.-H., Organometallics, 2004, 23, 976.
28.Wang H. M. J.; Lin I. J. B., Organometallics, 1998, 17, 972.
29.Lin, I. J. B.; Vasam, C. S., Coord. Chem. Rev., 2007, 251, 642.
30.Weskamp, T.; Schattenmann, W. C.; Spiegler, M.; Hermann, W. A., Angew. Chem., Int. Ed., 1998, 37, 2490.
31.Ahrens, S.; Herdtweck, E.; Goutal, S.; Strassner, T. Eur., J. Inorg. Chem., 2006, 1268.
32.Peris, E.; Loch, J. A.; Mata, J.; Crabtree, R. H. Chem. Commun. 2001, 201.
33.Lin, I. J. B.; Vasam, C. S., Can. J. Chem., 2005, 83, 812.
34.Chi, Y.; Chou, P.-T. Chem. Soc. Rev., 2010, 39, 638.
35.Kazuyoshi, T.; Shiki, Y.; Akihide, K., Takashi, K.; Kyoko, E.; Junji. M.; Seiji, A.; Masayoshi, Y., Eur. J. Inorg. Chem., 2010, 926.
36.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.
37.Tennyson, A. G.;Rosen, E. L.; Collins, M. S.; Lynch,V.M.; Bielawski, C. W., Inorg. Chem., 2009, 48, 6924.
38.Wheeler, S. E.; Houk, K. N., Molecular Physics, 2009, 107, 749.
39.Janiak, C., J. Chem. Soc., Dalton Trans., 2000, 3885.
40.Hunter, C. A.; Sanders, J. K. M., J. Am. Chem. Soc., 1990, 112, 5525.
41.Pomrnerehne, J.;Vestweber, H.;Gun, W.; Bassler,H.;Porsch, M.; Daub, J., Adv Muter, 1995, 7, 551
42.Burrows, P. E.; Shen, Z. ; Bulovic, V.; McCarty, D. M.; ForrestJ, S. R., Appl. Phys., 1996, 79 ,7991.
43.Sundberg, R. J.;Mente, D.C.;Yilmaz, I.;Gupta, G., J. Heterocycl. Chem., 1977, 1279.
44.Barczak, N. T.; Grote, R. E.; Jarvo, E. R., Organometallics , 2007, 26, 4863.
45.Zhang, X.; Gu,S.; Xia, Q.; Chen, W., J. Organomet. Chem., 2009, 694 , 2359.
46.Wang, X.; Liu, S.; Jin, G.-X., Organometallics, 2004, 23, 6002.
47.Hunter, C. A.; Sanders. J. K. M., J. Am. Chem. Soc., 1990, 112, 5525.
48.Gung, B. W.; Amicangelo, J. C., J. Org. Chem., 2006, 71, 9261.
49.Kim, H. G.; Lee, C.-W.; Yun, S.; Hong, B. H.; Kim, Y.-O.; Kim, D.; Ihm, H.; Lee, J. W.; Lee, E. C.; Tarakeshwar, P.; Park, S.-M.; Kim, K. S., Org. Lett., 2002, 4, 3971.
50.Au, V. K.-M.; Wong, K. M.-C.; Zhu, N.; Yam. V. W.-W., J. Am. Chem. Soc., 2009, 131, 9076.
51.Yi , C.; Cao, Q.-Y.; Yang, C.-J.; Huang, L.-Q.; Wang, J. H.; Xu, M.; Liu, J.; Qiu, P.; Gao, X.-C.; Li, Z.-F.; Wang, P., Inorganica Chimica Acta, 2006, 359, 4355.