Copper(I) Photoredox Catalysts Bearing Tetradentate Phenanthroline-Based Ligands: Understanding the Interplay between Structure and Function

Phenanthroline-based copper(I) complexes
represent some of the
earliest reported photoredox catalysts. Many of these species exhibit
poor coordinative stability and are prone to disproportionate in solution,
which can affect catalyst turnover and viability. This may also complicate
the elucidation of reaction mechanisms. In this study, the fundamental
properties of a library of copper(I) complexes that constitute six
general classes of tetradentate, phenanthroline-based supporting ligands
bearing covalently tethered neutral donor groups (e.g., phosphine,
phosphinite, phosphite, oxazoline or pyrazole moieties) were investigated.
These systems were employed to explore the relationship between structure
and function in copper(I) photoredox catalysis.

基于邻菲啰啉（phenanthroline）的铜(I)配合物（copper(I) complexes）是目前已报道的首批光氧化还原催化剂之一。这类配合物大多配位稳定性不佳，且在溶液中易发生歧化反应，这会干扰催化剂的周转过程并削弱其催化有效性，同时也会为反应机理的阐明带来额外难度。本研究针对一类铜(I)配合物库的基础性质展开探究，该库包含六大类以邻菲啰啉为骨架的四齿辅助配体，这些配体共价锚定有膦（phosphine）、亚膦酸酯（phosphinite）、亚磷酸酯（phosphite）、恶唑啉（oxazoline）或吡唑（pyrazole）等中性给体官能团。本研究借助该体系，探究了铜(I)光氧化还原催化中结构与功能之间的构效关系。