Visible-light induced photopolymerization mediated by Mn2(CO)10 in a continuous-flow process

• Versatile Mn 2 (CO) 10 photoinitiation successfully unifies conventional radical, controlled radical, and cationic polymerizations. • Continuous-flow processing in Corning Advanced-Flow™ and Vapourtec reactors ensures scalable and reproducible polymer synthesis. • Blue-light mediated protocols (405 nm) achieve high monomer conversions (up to 86%) under mild, energy-efficient conditions. • Inline 80 MHz 1 H NMR spectroscopy enables real-time reaction monitoring and precise kinetic regulation of the polymerization process. • Well-defined polymeric materials are produced with good narrow dispersities and tuneable molecular weights. • Sustainable manufacturing platform established for advanced materials, highlighting the synergy between organometallic catalysis and flow chemistry. Dimanganese decacarbonyl (Mn 2 (CO) 10 ) is used as a versatile and efficient visible-light photoinitiator for multiple polymerization techniques in different continuous-flow processes. The use of Mn 2 (CO) 10 results in efficient photoinitiation of the radical polymerization of methyl acrylate, while its ability to initiate methyl methacrylate polymerization is also demonstrated, as well as the cationic polymerisation of isobutyl vinyl ether (IBVE). In addition, the combination of Mn 2 (CO) 10 with certain Cu(II) catalysts affords controlled radical polymerization, yielding well-defined polymers with tuneable molecular weights under mild conditions. Polymerizations were performed under blue-light irradiation (λ = 405 nm) in a Corning Advanced-Flow™ reactor (CAFR). Copper-mediated protocols were also carried out in a Vapourtec flow reactor coupled with inline benchtop 80 MHz 1 H NMR allowing for real-time reaction monitoring. Inline and offline analyses, including NMR spectroscopy and size exclusion chromatography (SEC), confirmed relatively high monomer conversions (up to 86%) and the preparation of polymers with narrow dispersities ( Đ ≈ 1.09–1.15). The excellent photo reactivity of Mn 2 (CO) 10 , combined with the intrinsic advantages of continuous-flow processing, enables accurate regulation of residence time, light intensity, and initiator concentration. This work establishes a versatile platform for visible-light-mediated polymer synthesis, unifying conventional radical, controlled radical, and cationic processes within a single continuous-flow framework, and highlighting its potential for sustainable, scalable and environmentally benign manufacturing of advanced polymeric materials.