Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India.
J Fluoresc. 2011 Jul;21(4):1585-97. doi: 10.1007/s10895-011-0847-x. Epub 2011 Jan 28.
The synthesis, structure and photophysical properties of series of new luminescent cyclometalated Iridium (III) complexes are reported. The cyclometalated ligand used here is 2-aryl imidazole and the auxiliary ligand is acetyl acetone (acac). The crystal structure of the complex (dmdpi)(2)Ir(acac) (5) show that the Iridium(III) ion resides in a distorted octahedral environment. All complexes exhibit bright photoluminescence (PL) at room temperature and (fpdmdmpi)(2)Ir(acac) 4 has a high solution PL quantum efficiency of 0.56. The role played by electron releasing and electron withdrawing substituents of the 2-arylimidazole ligands towards the stability of HOMO and how the substituent influences the luminescent behaviour are discussed. Furthermore those substituents have effect on the contribution to mixing between (3)(π-π*) and (3)(MLCT) for the lowest excited states.
本文报道了一系列新型发光的金属环戊二烯铱（III）配合物的合成、结构和光物理性质。所用的金属环戊二烯配体为 2-芳基咪唑，辅助配体为乙酰丙酮（acac）。配合物(dmdpi)(2)Ir(acac)（5）的晶体结构表明，铱（III）离子位于扭曲的八面体环境中。所有配合物在室温下均表现出明亮的光致发光（PL），(fpdmdmpi)(2)Ir(acac)4 的溶液 PL 量子效率高达 0.56。讨论了 2-芳基咪唑配体的供电子和吸电子取代基对 HOMO 稳定性的作用，以及取代基如何影响发光行为。此外，这些取代基对最低激发态中（3）（π-π*）和（3）（MLCT）之间混合的贡献有影响。
