PHOTOBOX

Visible light photocatalysis has emerged as a crucial technique for activating small molecules through radical pathways, with over 34,000 publications on the subject since 2008, highlighting its rapid growth. This method leverages the photophysical properties of photocatalysts (PCs) that can initiate electron and energy transfers under mild conditions, enabling previously difficult transformations. Common PCs, such as ruthenium and iridium polypyridyl complexes and organic dyes, have well-documented photophysical data, allowing prediction of their reactivity in photoredox processes. However, these transition metal catalysts are expensive due to their scarcity, and organic dyes suffer from instability due to photobleaching. Additionally, the recycling of homogeneous PCs is challenging because of the difficulty in separating them from reaction mixtures. In response to these limitations, the PHOTOBOX project seeks to develop novel, recyclable, and metal-free photocatalysts that surpass traditional ones. The project focuses on utilizing the recyclability and tunability of solid-state p-conjugated organic polymers as heterogeneous photocatalysts (hPCs). These materials will provide a sustainable alternative to current homogeneous systems. Building on previous research on poly-(arylene-ethynylenes) (PAE), the project aims to design new hPCs with varied electronic properties by incorporating donor (D) and acceptor (A) groups. Detailed structural, surface, and photophysical analyses will support the development of a toolbox of hPCs with tailored properties for broad chemical applications. The toolbox's effectiveness will be demonstrated through visible light-driven transformations of challenging substrates, such as SF6 and benzene rings on the reductive side, and toluene and fluorobenzene derivatives on the oxidative side. These transformations will be applied to late-stage functionalization of bioactive compounds and the synthesis of natural product precursors and drugs. When feasible, continuous-flow processes will be explored to improve control over reaction parameters, ensuring reproducibility and scalability.