(1-(Phenanthrolo[5,6-d]imidazol-2-yl)-3-(4,5-diphenylimidazol-2-yl)benzene

Hui Chao*, Cai-Wu Jiang, Hao Zhang and Liang-Nian Ji**

State Key Laboratory of Optoelectronic Materials and Technologies / Department of Chemistry, Zhongshan University, Guangzhou 510275, P. R. China

E-mail:  *[email protected], **[email protected]

Received: 2 April 2002 / Accepted: 16 May 2002 / Published: 20 February 2003

Keywords: polypyridine ligands, phenanthroline, benzil

2-(3-Formylphenyl)imidazo[4,5-f][1,10]phenanthroline was prepared by a previously published method [1]. A mixture of 2-(3-formylphenyl)imidazo[4,5-f][1,10]phenanthroline (0.25 g, 0.77 mmol), benzil (0.16 g, 0.77 mmol), ammonium acetate (1.19 g, 15.4 mmol) and glacial acetic acid (10 cm³) was refluxed for about 2 h. The cooled solution was filtered, diluted with water (about 60 cm³) and neutralized with concentrated aqueous ammonia. The precipitate was collected and purified by column chromatography on alumina with ethanol-toluene (1:2 v/v) as eluent to give the title compound as a pale yellow powder. Yield 0.27 g, 67.7%.

¹H NMR (500 MHz, d₆-DMSO): 13.95 (s, 1H), 13.07 (s, 1H), 9.24 (s, 1H), 9.05 (d, 2H, J = 8), 9.00 (d, 2H, J = 8), 8.29 (d, 1H, J = 8), 8.25 (d, 1H, J = 8), 7.93 (d, 2H, J = 6.5), 7.83 (m, 3H), 7.74 (t, 1H, J = 8), 7.57 (d, 2H, J = 7), 7.57 (t, 1H, J = 8), 7.36 (t, 2H, J = 8), 7.28 (t, 2H, J = 7.0).

¹³C NMR (125 MHz, d₆-DMSO): 150.3, 147.8, 145.0, 143.7, 137.4, 135.7, 135.1, 131.1, 130.9, 130.5, 129.6, 129.3, 128.5, 128.1, 127.7, 127.2, 126.6, 126.1, 125.9, 123.7, 123.3, 123.0, 119.3.

IR (KBr. cm^-1): 3430, 1629, 1564, 1481, 1451, 1412, 1385, 1352, 1259, 1077, 1026, 1001, 968, 809, 766, 737, 698.

UV-Vis (l, nm, in ethanol): 288, 304.

FAB-MS ([M+1]⁺): 515.

Acknowledgement: Support for this research provided by the National Natural Science Foundation of China, the National Science Foundation of Guangdong Province and Research Fund of Royal Society of Chemistry U.K. is gratefully acknowledged.

References and Notes

1. Chao, H.; Ye, B.-H.; Li, H.; Li, R.-H.; Zhou, J.-Y.; Ji, L.-N. Polyhedron 2000, 19, 1975.

Sample availabylitiy: available from the authors

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