Near-infrared photothermal conversion of stable radicals photoinduced from a viologen-based coordination polymer

Upon simple UV-visible irradiation, a viologen-based coordination polymer was transformed to a highly stable radical, protected against quenching by a densely packed structure. The photo-generated radical exhibited a remarkable near-infrared (NIR) photothermal effect with good recyclability and high conversion efficiency. To our knowledge, this is the first example of a crystalline viologen-based coordination polymer that functions as a NIR photothermal material by forming stable radicals.