Light-Harvesting Antennae using the Host-Guest Chemistry of Mesoporous Organosilica

This study presents two series of new host-guest chromophoric systems, where BODIPY dyes are organized into mesoporous silica. The dyes self-assemble with surfactants to generate micellar templates that can direct the formation of the silica networks. The materials were characterized by means of small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) to elucidate their structure, and by UV/Vis absorption spectroscopy to determine their optical properties. Dye-loaded COK-12 materials retain an ordered structure and exhibit a green fluorescence that slightly red-shifts and undergoes quenching as the dye loading increases. A second system is based on MCM-41 silica and works as a polychromatic antenna, where a high energy species forms within the template and drive excitation energy transfer in timescales down to 20ps. Such systems show promising performances for the realization of photonic antennae, to be used as sensitizers for solar cells and photocatalytic devices.