Modular One-Pot Construction of Solar Azo-Switches Based on Heteroaryl Organozinc Reagents

Solar azo-switches, as a newly emerging class of azo molecules, hold great promise for solar energy storage and conversion. However, the synthetic complexity and structural rigidity have limited the economic feasibility and functional diversification of such azo compounds. Inspired by the application of organozinc reagents in synthesis, we developed a modular one-pot synthetic approach for solar azo molecules based on heteroaryl organozinc reagents in this study. This "one-pot" method features a simple operation with commercially available substrates, demonstrating adaptability to various heteroaryl structures and functional groups. These molecules exhibit excellent isomerization efficiency (up to 87%) under unfiltered sunlight and demonstrate tunable half-lives of the Z isomer ranging from seconds to months. Notably, the fluorinated azo compound showed particular promise with a half-life of 157 days, which is the longest reported to date among solar mono-azo molecules.