Kinetics of 1,3-dipolar cycloaddition on the surfaces of Au nanoparticles

Triazole formation via 1,3-dipolar cycloaddition, or click chemistry, is a powerful synthetic method for incorporating chemical functionality onto the surfaces of Au nanoparticles. To investigate the factors that govern azide/alkyne reactivity at particle surfaces, we measured the general kinetic trends for the uncatalyzed reaction using FTIR spectroscopy. This study examines the roles of ligand length, electronic substitution of the alkyne species, and solvent on the reaction under pseudo-first-order conditions. The conversion of azide to triazole is found to depend more strongly on the relative surface coverage of azide terminated alkanethiol than on the ligand length and solvent. (C) 2007 Elsevier Inc. All rights reserved.