title: Reaction network governing diphosphine-protected gold nanocluster formation from nascent cationic platforms.
abstract: We identify the reaction network governing gold monolayer protected cluster (MPC) formation during the reduction of Au(PPh(3))Cl and L(5) (L(5) = 1,5-bis(diphenylphosphino)pentane) in solutions. UV-vis spectroscopy and electrospray ionization mass spectrometry (ESI-MS) monitored the formation of ligated Au(x): 6 ≤ x ≤ 12 clusters, which comprise the reaction intermediates and final products. Initially, predominantly [Au(2)L(5)(2)](2+) complexes form through dissolution of Au(PPh(3))Cl. These complexes control the reduction and nucleation reactions that form nascent phosphine-ligated Au(8) and Au(10) ionic clusters. [Au(10)L(5)(4)](2+) is an observed growth platform for ligated Au(11) and Au(12) clusters. The data for syntheses of Au : L(5) systems evidence that the nascent reaction products (t < 3 days) are less dependent on the chosen reducing agent (borane tert-butylamine complex or NaBH(4)); instead, after reduction ceases, subsequent solution phase processing provides greater control for tuning cluster nuclearity.
authors.affiliation: Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, MS-8320, Gaithersburg, MD 20899-8320, USA. john.pettibone@nist.gov
authors.forename: John M
authors.initials: JM
authors.lastname: Pettibone
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Hudgens
mesh_terms: D002412:Cations / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry*
chemical_list: D002412:Cations; D009942:Organometallic Compounds; D010720:Phosphines; D006046:Gold