title: Radicals Are Required for Thiol Etching of Gold Particles.
abstract: Etching of gold with an excess of thiol ligand is used in both synthesis and analysis of gold particles. Mechanistically, the process of etching gold with excess thiol is unclear. Previous studies have obliquely considered the role of oxygen in thiolate etching of gold. Herein, we show that oxygen or a radical initiator is a necessary component for efficient etching of gold by thiolates. Attenuation of the etching process by radical scavengers in the presence of oxygen, and the restoration of activity by radical initiators under inert atmosphere, strongly implicate the oxygen radical. These data led us to propose an atomistic mechanism in which the oxygen radical initiates the etching process.
authors.affiliation: Chemistry, Colorado State University, 1847 Campus Deliver, Fort Collins, CO 80523 (USA).
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Dreier
authors.affiliation: Chemistry, Colorado State University, 1847 Campus Deliver, Fort Collins, CO 80523 (USA). Ackerson@colostate.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Ackerson
mesh_terms: D016166:Free Radical Scavengers / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D010316:Particle Size; D010713:Phosphatidylcholines / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D016166:Free Radical Scavengers; D010713:Phosphatidylcholines; D013438:Sulfhydryl Compounds; D006046:Gold
keywords: etching; gold nanoclusters; nanoparticles; thiolates