Self-Assembled Monolayers Based Upon a Zirconium Phosphate Platform

Abstract

Organically surface-modified α-zirconium phosphate was obtained by reacting the surface P–O–H groups of α-zirconium phosphate nanoparticles (α-ZrP) with octadecyltrichlorosilane (OTS). Surface functionalization of α-ZrP with OTS was accomplished using a one-step synthesis producing highly hydrophobic nanoparticles. The formation of P–O–Si bonds arising from nucleophilic attack of POH to the silane was confirmed by solid-state NMR experiments. The surface coverage of the organic modifier was characterized by TGA, AFM, and FTIR. In addition, we show the applicability of this system with a photoinduced electron-transfer reaction in a nonpolar solvent. Using an organically surface-modified α-ZrP previously loaded with tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+), the quenching of the luminescence of Ru(bpy)32+ in the presence of p-benzoquinone was monitored; a static quenching constant (Ks) value of 8.82 × 102 M–1 and a dynamic quenching constant (KD) value of 6.99 × 102 M–1 were obtained.