Chiral modification of metal nanoparticle surfaces

Abstract

The aim of this project is to introduce chirality onto surfaces of transition metal nanoparticles. Chirally modified metal nanoparticles were synthesized by two methods: i) a one-step method involving pre-preparation of chiral potassium xanthates and use of these xanthates for synthesis of gold and silver nanoparticles; ii) a two-step method related to esterification of chiral alcohols with MUA-capped gold nanoparticles and chiral phosphate with MUO-capped gold nanoparticles. Xanthates were found to play the role as a good capping agent and can be used as a contaminant-free substitute for both alkylthiol and TOAB in the conventional Brust-Schiffrin synthesis of metal nanoparticles. Esterification reactions of chiral alcohols with MUA-capped gold nanoparticles and chiral phosphates with MUO-capped gold nanoparticles were demonstrated to be conducted under mild conditions by utilizing BOP and triphenylphosphine-tetrachloromethane as catalysts. Vibrational circular dichroism spectra of L-menthylxanthate gold and silver nanoparticles were predicted by DFT computations.