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.