Lamansky S, Djurovich P, Murphy D, Abdel-Razzaq F, Kwong R, Tsyba I, Bortz M, Mui B, Bau R, Thompson M E
Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA.
Inorg Chem. 2001 Mar 26;40(7):1704-11. doi: 10.1021/ic0008969.
The preparation, photophysics, and solid state structures of octahedral organometallic Ir complexes with several different cyclometalated ligands are reported. IrCl3.nH2O cleanly cyclometalates a number of different compounds (i.e., 2-phenylpyridine, 2-(p-tolyl)pyridine, benzoquinoline, 2-phenylbenzothiazole, 2-(1-naphthyl)benzothiazole, and 2-phenylquinoline), forming the corresponding chloride-bridged dimers, CwedgeN2Ir(mu-Cl)2IrCwedgeN2 (CwedgeNis a cyclometalated ligand) in good yield. These chloride-bridged dimers react with acetyl acetone (acacH) and other bidentate, monoanionic ligands such as picolinic acid (picH) and N-methylsalicylimine (salH), to give monomeric CwedgeN2Ir(LX) complexes (LX = acac, pic, sal). The emission spectra of these complexes are largely governed by the nature of the cyclometalating ligand, leading to lambda(max) values from 510 to 606 nm for the complexes reported here. The strong spin-orbit coupling of iridium mixes the formally forbidden 3MLCT and 3pi-pi* transitions with the allowed 1MLCT, leading to a strong phosphorescence with good quantum efficiencies (0.1-0.4) and room temperature lifetimes in the microsecond regime. The emission spectra of the CwedgeN2Ir(LX) complexes are surprisingly similar to the fac-IrCwedgeN3 complex of the same ligand, even though the structures of the two complexes are markedly different. The crystal structures of two of the CwedgeN2Ir(acac) complexes (i.e., CwedgeN = ppy and tpy) have been determined. Both complexes show cis-C,C', trans-N,N' disposition of the two cyclometalated ligands, similar to the structures reported for other complexes with a "CwedgeN2Ir" fragment. NMR data (1H and 13C) support a similar structure for all of the CwedgeN2Ir(LX) complexes. Close intermolecular contacts in both (ppy)2Ir(acac) and (tpy)2Ir(acac) lead to significantly red shifted emission spectra for crystalline samples of the ppy and tpy complexes relative to their solution spectra.
报道了具有几种不同环金属化配体的八面体有机金属铱配合物的制备、光物理性质和固态结构。IrCl3·nH2O能顺利地与多种不同化合物（如2-苯基吡啶、2-（对甲苯基）吡啶、苯并喹啉、2-苯基苯并噻唑、2-（1-萘基）苯并噻唑和2-苯基喹啉）发生环金属化反应，以良好的产率形成相应的氯桥联二聚体C∧N2Ir（μ-Cl）2IrC∧N2（C∧N为环金属化配体）。这些氯桥联二聚体与乙酰丙酮（acacH）以及其他双齿单阴离子配体如吡啶甲酸（picH）和N-甲基水杨酰亚胺（salH）反应，得到单体C∧N2Ir（LX）配合物（LX = acac、pic、sal）。这些配合物的发射光谱在很大程度上由环金属化配体的性质决定，本文报道的配合物的最大波长值在510至606 nm之间。铱的强自旋-轨道耦合使形式上禁阻的3MLCT和3π-π*跃迁与允许的1MLCT混合，导致强磷光，具有良好的量子效率（0.1 - 0.4）和微秒级的室温寿命。C∧N2Ir（LX）配合物的发射光谱与相同配体的面式-IrC∧N3配合物惊人地相似，尽管这两种配合物的结构明显不同。已测定了两种C∧N2Ir（acac）配合物（即C∧N = ppy和tpy）的晶体结构。两种配合物中两个环金属化配体均呈现顺式-C、C'，反式-N、N'构型，与报道的其他具有“C∧N2Ir”片段的配合物结构相似。核磁共振数据（1H和13C）支持所有C∧N2Ir（LX）配合物具有相似的结构。（ppy）2Ir（acac）和（tpy）2Ir（acac）中紧密的分子间接触导致ppy和tpy配合物晶体样品的发射光谱相对于其溶液光谱发生显著红移。
