Micellar (Photo-)Catalysis driven by IR-Active Semiconductor Surfactants

In micellar catalysis, one uses aggregates formed by surfactants as nanoreactors for performing chemical reactions. A special class of tailor-made surfactants containing catalytically active sites opens new perspectives in micellar catalysis. Little is known about the combination of such surfactants with photocatalysis. Molecular semiconductors are presented, which simultaneously have amphiphilic properties and are made of a hydrophilic fullerenol head group attached to dye molecules as the hydrophobic entity. The first generation of those surfactants produces reactive oxygen species (ROS) when exposed to light in the UV/Vis range. The concept of the current paper is that one can drive the photocatalytic process also using low-energy photons in the near-infrared region. For this purpose, NIR-active dye molecules were selected and attached to the fullerenol head. It is shown that a fullerenol - aminostilbene compound representing the second generation of semiconductor surfactants fulfills all requirements. It forms aggregates in water that are catalytically active. Moreover, two-photon experiments with lamda = 780 nm were performed, indicating successful ROS production and, thus, photocatalytic activity.