Design and Synthesis of Tris-Heteroleptic Cyclometalated Iridium(111) Complexes Consisting of Three Different Nonsymmetric Ligands Based on Ligand-Selective Electrophilic Reactions via Interligand HOMO Hopping Phenomena
Design and Synthesis of Tris-Heteroleptic Cyclometalated Iridium(111) Complexes Consisting of Three Different Nonsymmetric Ligands Based on Ligand-Selective Electrophilic Reactions via Interligand HOMO Hopping Phenomena
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DOI：
10.1021/acs.inorgchem.6b02519
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发表时间：
2017-01-16
影响因子：
4.6
通讯作者：
Aoki, Shin
中科院分区：
文献类型：
--
作者：
Hisamatsu, Yosuke;Kumar, Sarvendra;Aoki, Shin
在这篇文章中，我们报告成功的合成和分离的环化铱配合物具有三个不同的非对称配体的基础上通过配体间HOMO（最高占据分子轨道）跳跃现象的配体选择性亲电反应。据推测，具有8-苯磺酰胺基喹啉作为辅助配体的双杂配型Jr配合物5a和7的亲电取代反应将在这些Jr配合物的喹啉环的5位进行，得到18和19，因为它们的HOMO位于喹啉环上，如密度泛函理论（DFT）计算所预测的。在这些产物中，HOMO被转移到两个ppy配体之一中，其中苯基反式到Ir N（喹啉的1位）键，因此，18和19的碘化或取代发生在ppy配体的5'位，以提供20 a、23和24。此外，我们使用交叉偶联反应对20 a进行官能化，以良好的产率获得含有三种不同配体的三杂配体配合物Jr，非对映体的形成可以忽略不计。还报道了新的双发射三杂配环化Ir配合物21-24的光化学性质，特别是双发射和对pH变化的响应。
In this article we report on the successful synthesis and isolation of cyclometalated Ir complexes having three different nonsymmetric ligands based on ligand-selective electrophilic reactions via interligand HOMO (highest occupied molecular orbital) hopping phenomena. It was hypothesized that the electrophilic substitution reactions of bis-heteroleptic Jr complexes having 8-benzenesulfonamidoquinoline as an ancillary ligand, 5a and 7, would proceed at the 5 position of the quinoline ring of these Jr complexes to afford 18 and 19, because their HOMOs are localized on the quinoline rings, as predicted by density,functional theory (DFT) calculations. In these products, the HOMO is transferred to one of two ppy ligands, in which the phenyl group is trans to the Ir N (1 position of quinoline) bond, and hence, the iodination or formylation of 18 and 19 occurs at the 5' position of the ppy ligand to provide 20a, 23, and 24. Furthermore, we carried out the functionalization of 20a using cross-coupling reactions to obtain tris-heteroleptic Jr complexes containing three different ligands in good yields with negligible diastereomer formation. Photochemical properties, especially dual emission, and response to pH change, of new dual emissive tris-heteroleptic cyclometalated Ir complexes, 21-24, are also reported.