Corrole and corrole functionalized silica nanoparticles as new metal ion chemosensors: a case of silver satellite nanoparticles formation.

Corrole macrocycles are very appealing dyes for incorporation into light harvesting devices. This work shows the sensorial ability of 5,10,15-tris(pentafluorophenyl)corrole 1 and its monoanionic species toward Na(+), Ca(2+), Cu(2+), Cd(2+), Pb(2+), Hg(2+), Ag(+), and Al(3+) metal ions in toluene and acetonitrile. The photophysical studies toward metal ions were carried out by absorption and emission spectroscopy. From all metal ions studied, corrole 1 shows to be colorimetric for Hg(2+) allowing a naked-eye detection of Hg(2+) through a change of color from purple to blue in acetonitrile and from green to yellow in toluene. In addition a new β-imine corrole 4 was successful synthesized and further functionalized with 3-isocyanatopropyl-trimethoxysilane resulting in an alkoxysilane derivative 5. The grafting of alkoxysilane derivative 5 with optically transparent silica nanoparticles (SiNPs) was achieved succesfully. The new-coated silica nanoparticles with corrole 5 were studied in the presence of Cu(2+), Hg(2+), and Ag(+) as metal ion probes. Interestingly, upon addition of Ag(+), groups of satellite AgNPs were formed around the SiNPs and were checked by transmission electron microscopy (TEM). At same time, a change of color from green to yellow was observed.