We present a novel reversible deactivation radical polymerization (RDRP) using dithiocarbonyl compounds as the initiator-mediator combo and upconversion nanoparticles as internal light sources under the irradiation of near-infrared (NIR) light. Polymerization of butyl acrylate, vinyl acetate and methyl methacrylate was possible using this method. Polymers with a well-defined structure were obtained. Excellent end-group fidelity of the polymers was well demonstrated by nuclear magnetic resonance and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. NIR light, with a strong penetration capability and low energy, is an attractive candidate as a light source for photo-induced RDRP, particularly for systems containing insensitive bonds.
