Overcoming the Oxygen Dilemma in Photoredox Catalysis: Near‐Infrared (NIR) Light‐Triggered Peroxynitrite Generation for Antibacterial Applications.

The peroxynitrite anion (ONOO−) is closely associated with many diseases and the creation of ONOO− donors is an essential means of understanding its pathophysiological functions. However, it is challenging to develop ONOO− donors due to the difficulties in simultaneously producing highly reactive and short‐lived nitric oxide (NO) and superoxide anion (O2⋅−). Here, we report a novel strategy for constructing ONOO− donors by combining near‐infrared (NIR)‐mediated type I photosensitization and photoredox catalysis. The key design using a Nile blue analogue that can serve as both a type I photosensitizer and a metal‐free photocatalyst. Intriguingly, the formation of O2⋅− via type I photosensitization avoids oxygen interference and instead activates nitrobenzofurazan‐based NO donors via oxygen‐tolerant NIR photoredox catalysis. The simultaneous release of O2⋅− and NO leads to ONOO− release, showing both antibacterial and antibiofilm activities. [ABSTRACT FROM AUTHOR]