title: Kinetic control and thermodynamic selection in the synthesis of atomically precise gold nanoclusters.
abstract: This work presents a combined approach of kinetic control and thermodynamic selection for the synthesis of monodisperse 19 gold atom nanoclusters protected by thiolate groups. The step of kinetic control allows the formation of a proper size distribution of initial size-mixed Au(n)(SR)(m) nanoclusters following the reduction of a gold precursor. Unlike the synthesis of Au(25)(SR)(18) nanoclusters, which involves rapid reduction of the gold precursor by NaBH(4) followed by size focusing, the synthesis of 19-atom nanoclusters requires slow reduction effected by a weaker reducing agent, borane-tert-butylamine complex. The initially formed mixture of nanoclusters then undergoes size convergence into a monodisperse product by means of a prolonged aging process. The nanocluster formula was determined to be Au(19)(SC(2)H(4)Ph)(13). This work demonstrates the importance of both kinetic control of the initial size distribution of nanoclusters prior to size focusing and subsequent thermodynamic selection of stable nanoclusters as the final product.
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA. zkwu@issp.ac.cn
authors.forename: Zhikun
authors.initials: Z
authors.lastname: Wu
authors.forename: Mark A
authors.initials: MA
authors.lastname: MacDonald
authors.forename: Jenny
authors.initials: J
authors.lastname: Chen
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Rongchao
authors.initials: R
authors.lastname: Jin
mesh_terms: D006046:Gold; D007700:Kinetics; D053768:Metal Nanoparticles; D049329:Nanostructures; D010316:Particle Size; D019163:Reducing Agents; D013438:Sulfhydryl Compounds; D013816:Thermodynamics
chemical_list: D019163:Reducing Agents; D013438:Sulfhydryl Compounds; D006046:Gold