A persistent radical anion naphthalenediimide-based hybrid material for near-infrared photothermal conversion and photocatalytic oxidative organic transformations

Abstract

Persistent radical-containing hybrid materials are a focus of attention due to their functions such as photomodulated electrical conductivity, magnetism, and photochromism. Such hybrid materials are relatively underexplored, however, mainly due to the lack of suitable highly photoactive building blocks. In this work, a hybrid material SiMo-NDI with persistent radical anions was rationally designed and prepared by incorporating photoactive naphthalenediimides (NDIs) and polyoxometallate into its structure. Characterization of SiMo-NDI not only confirmed its photochromism and narrow band gap, but also revealed the radical derived from photoinduced electron transfer between the NDI and electron donor. The persistent radical and strong near-infrared absorption characteristics of this hybrid material enable effective near-infrared photothermal conversion. Moreover, it can efficiently generate superoxide radical anions under light irradiation which promote the photocatalytic hydroxylation of arylboronic acids and C-3 thiocyanation of indoles in high yield with good recyclability at room temperature and without additives.