SbPh3-based organic molecular cage for size-controlled preparation and stabilization of palladium nanoparticles

Abstract

Group 15 triphenyl compounds with coordination ability such as triphenylamine (NPh3) and triphenylphosphine (PPh3) have been widely investigated for the construction of functional porous organic materials. In this work, a SbPh3-based organic molecular cage (Sb-cage) was unprecedently synthesized. The spatial configuration of Sb-cage was precisely analyzed by single crystal X-ray diffraction, showing a trigonal–bipyramidal [2 + 3] assembly. Sb-cage was employed to the mediated growth of palladium nanoparticles (PdNPs) with an average diameter of 0.70 nm. As-synthesized utrafine PdNPs exhibits good catalytic activity in Suzuki-Miyaura coupling reaction between aryl halides and phenylboronic acid, where the PdNPs could grow up in situ to a stable size distribution of 1.71 ± 0.30 nm. Furthermore, the advantages of the trigonal bipyramidal configuration in the stabilization of metal nanoparticles during the catalytic reaction cycles were demonstrated via the control experiments on SbPh3-based unclosed semicage.