期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 144, 期 25, 页码 11189-11202出版社
AMER CHEMICAL SOC
DOI: 10.1021/jacs.2c02011
关键词
-
资金
- Australian Research Council [DP200102947, DE210101168, DP220100300]
- Australian Research Council [DE210101168, DP200102947] Funding Source: Australian Research Council
In this work, the scope of a previously demonstrated side reaction in heteroleptic iridium(III) complexes was explored using high throughput synthesis and screening under photochemical conditions. The compositions of the ancillary ligands were found to be crucial in determining the different chemical pathways and the photochemical stability of the complexes.
Photoredox catalysts are primarily selected based on ground and excited state properties, but their activity is also intrinsically tied to the nature of their reduced (or oxidized) intermediates. Catalyst reactivity often necessitates an inherent instability, thus these intermediates represent a mechanistic turning point that affords either product formation or side-reactions. In this work, we explore the scope of a previously demonstrated side reaction that partially saturates one pyridine ring of the ancillary ligand in heteroleptic iridium(III) complexes. Using high throughput synthesis and screening under photochemical conditions, we identified different chemical pathways, ultimately governed by ligand composition. The ancillary ligand was the key factor that determined photochemical stability. Following photoinitiated electron transfer from a sacrificial tertiary amine, the reduced intermediate of complexes containing 1,10-phenanthroline derivatives exhibited long-term stability. In contrast, complexes containing 2,2'-bipyridines were highly susceptible to hydrogen atom transfer and ancillary ligand modification. Detailed characterization of selected complexes before and after transformation showed differing effects on the ground and excited state reduction potentials dependent on the nature of the cyclometalating ligands and excited states. The implications of catalyst stability and reactivity in chemical synthesis was demonstrated in a model photoredox reaction.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据