title: Prediction of nonradical Au(0)-containing precursors in nanoparticle growth processes.
abstract: This density functional theory (DFT) investigation examines the formation of nonradical Au(0) species from the reduction of Au(I) species. The Au(I) complexes of interest are AuCl2(-), AuBr2(-), AuI2(-), AuClPH3, and AuCl(H)SCH3(-), which are precursors for gold nanoparticle and cluster formation. Reaction of two of the Au(I) species with a hydride results in ejection of two of the ligands and formation of Au2 with two ligands still attached. AuX2(-) (where X = Cl, Br, or I) reactions eject two halides and form Au2X2(2-). AuClL(-) (where L = PH3, HSCH3, or SCH3(-)) reactions can eject either chloride, HCl, PH3, HSCH3, or SCH3(-) and form Au(0)L2(q-) or Au(0)ClL(q-) (q = 0, 1, 2). The Au2Cl2(2-) complex can further react with AuCl2(-), which forms Au3Cl3(2-) and a chloride anion. The new Au3Cl3(2-) species can then react with AuCl2(-) or Au2Cl2(2-) or with another Au3Cl3(2-). Larger clusters can be formed from these precursors. In this work, reactions in both methanol and benzene solvents are considered as models for one-phase and two-phase gold nanoparticle growth processes. Overall, this investigation shows how Au(0)-containing species can be formed without assuming the formation of Au(0) atoms (radical species).
authors.affiliation: Department of Chemistry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Barngrover
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Manges
authors.forename: Christine M
authors.initials: CM
authors.lastname: Aikens
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D050607:Organogold Compounds / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D050607:Organogold Compounds; D006046:Gold