Stereospecific Synthesis of Tris-heteroleptic Tris-cyclometalated Iridium(III) Complexes via Different Heteroleptic Halogen-Bridged Iridium(III) Dimers and Their Photophysical Properties
Stereospecific Synthesis of Tris-heteroleptic Tris-cyclometalated Iridium(III) Complexes via Different Heteroleptic Halogen-Bridged Iridium(III) Dimers and Their Photophysical Properties
复制标题
DOI：
10.1021/acs.inorgchem.8b00323
复制
发表时间：
2018-04-16
影响因子：
4.6
通讯作者：
Aoki, Shin
中科院分区：
文献类型：
--
作者：
Tamura, Yuichi;Hisamatsu, Yosuke;Aoki, Shin
本文报道了三种不同的非对称环化配体通过卤素桥连的三配位三环化铱（III）（Ir（III））配合物[Ir（tpy）（F（2）ppy）（mu-Br）]（2）17 b和[Ir（mpiq）（F（2）ppy）（mu-Br）]（2）27 b的立体定向合成（tpyH：（2-（4 ′-甲苯基）吡啶）和F（2）ppyH：（2-（4 ′，6 ′-二氟苯基）吡啶）和mpiqH：（1-（4 ′-甲基苯基）异喹啉））。然后，通过光谱数据和X射线晶体结构分析确认，17 b和27 b转化为由tpy、F（2）ppy和mpiq组成的三环杂配Ir配合物Ir（tpy）（F（2）ppy）（mpiq）25。在这项工作中的第一个重点是特定的异构体的选择性合成八个可能的立体异构体的铱配合物具有相同的组合的三个环化配体。也就是说，合成并分离了25的两种甾醛形式。第二个发现是25的不同立体异构体具有不同的稳定性。最后，不同的立体异构体表现出不同的发射光谱。也就是说，其立体异构体25 a之一表现出从ca. 550 nm至约650 nm（橙子发射），而立体异构体25 c在约650 nm处发射双重发射。509 nm和ca. 600 nm（淡粉红色发射），如依赖于时间的密度泛函理论计算所支持的。据我们所知，这是第一个报告的选择性和有效的合成不同的立体异构体的三杂配型三环取代铱（III）配合物，具有不同的稳定性和不同的物理化学性质。
Herein, we report on the stereospecific synthesis of two single isomers of tris-heteroleptic tris-cyclometalated iridium(III) (Ir(III)) complexes composed of three different nonsymmetric cyclometalating ligands via heteroleptic halogen-bridged Ir dimers [Ir(tpy)(F(2)ppy)(mu-Br)](2) 17b and [Ir(mpiq)(F(2)ppy)(mu-Br)](2) 27b (tpyH: (2-(4'-tolyl)pyridine) and F(2)ppyH: (2-(4',6'-difluorophenyl)pyridine), and mpiqH: (1-(4'-methylphenyl)isoquinoline)) prepared by Zn2+-promoted degradation of Ir(tpy)(2)(F(2)ppy) 21 and Ir-(mpiq)(2)(F(2)ppy) 26, as reported by us. Subsequently, 17b and 27b were converted to the tris-heteroleptic tris-cyclometalated Ir complexes Ir(tpy)(F(2)ppy)(mpiq) 25 consisting of tpy, F(2)ppy, and mpiq, as confirmed by spectroscopic data and X-ray crystal structure analysis. The first important point in this work is the selective synthesis of specific isomers among eight possible stereoisomers of Ir complexes having the same combination of three cyclometalating ligands. Namely, two meridional forms of 25 were synthesized and isolated. The second finding is that the different stereoisomers of 25 have different stability. Finally, different stereoisomers exhibit different emission spectra. Namely, one of its stereoisomers 25a exhibits a single broad emission from ca. 550 nm to ca. 650 nm (orange emission), while stereoisomer 25c emits dual emission at ca. 509 nm and ca. 600 nm (pale pink emission), as supported by time-dependent density functional theory calculation. To the best of our knowledge, this is the first report of the selective and efficient synthesis of different stereoisomers of tris-heteroleptic tris-cyclometalated Ir(III) complexes that have different stabilities and different photophysical properties.