14337-12-3Relevant articles and documents
pH-insensitive fabrication of gold nanoparticles with high concentration by ultrasound-assisted electrochemical process via aid of chitosan
Yang, Kuang-Hsuan,Liu, Yu-Chuan,Hsu, Ting-Chu,Tsai, Huei-Ian
, p. 63 - 68 (2010)
In this work, we report a new pathway to prepare pure gold nanoparticles with high concentrations in acid solutions via the aid of chitosan without the addition of other stabilizers and reductants based on electrochemical methods. Interestingly, this fabrication of gold nanoparticles with high concentrations in solutions is pH-insensitive. The characteristics of prepared gold nanoparticles were examined by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (HRXPS) measurements. Experimental results indicate the concentration and the particle size of Au nanoparticles prepared in 0.1N HCl are ca. 50 ppm and 12 nm in diameter, respectively. Similar experiment performed in 0.1N NaCl with the aid of chitosan shows that the corresponding concentration of prepared Au nanoparticles is ca. 100 ppm. Further similar experiments performed in 0.1N HCl and 0.1N NaCl without the aid of chitosan show that the corresponding concentrations of prepared Au nanoparticles are ca. 1 and 60 ppm, respectively.
Decamethylferrocene redox chemistry and gold nanowire electrodeposition at salt crystal|electrode|nonpolar organic solvent contacts
Watkins, John D.,Hotchen, Christopher E.,Mitchels, John M.,Marken, Frank
, p. 2616 - 2620 (2012)
This report describes exploratory experimental findings for electrochemical processes in nonpolar solvents (hexane, toluene, and dichloroethane). Conventional 3 mm diameter glassy-carbon-disk electrodes are used in contact with a crystalline salt electrolyte (ammonium nitrate) immersed in nonpolar solvents. The insoluble salt is employed as a "surface thin film electrolyte", with humidity causing electrical connection from the working electrode to the SCE counter-reference electrode. The organic solvents are employed without intentionally added electrolyte. Humidity in the nonpolar solvents is shown to be essential for the processes to work. The oxidation of decamethylferrocene is demonstrated as a test organometallic redox system. The electrochemical reduction of Au(III) in toluene (solubilized with tetraoctylammonium bromide, TOABr) is employed to demonstrate and visualize the reaction zone around salt crystal|working electrode contact points. Gold nanowire bundle formation is observed, presumably due to an ordered interfacial surfactant microphase at salt|electrode contact points. The triple phase boundary nature of these processes is discussed, and future applications are suggested.
Gold(III) extraction by 1,3-Bis(2'-acetoxymethylthiobutyl-3'- thiobutylpropyl)-6-methyluracyl from hydrochloric acid solutions
Khisamutdinov,Murinov,Baikova
, p. 1798 - 1802 (2007)
Gold(III) extraction by 1,3-bis(2'-acetoxymethylthiobutyl-3'- thiobutylpropyl)-6-methyluracyl from 0.5 M HCl solutions to chloroform is studied. The reagent has a high efficiency, separates gold(III) ions from the sum of nonprecious and ferrous metals, and can be repeatedly used after stripping. The extraction mechanism is solvation, with Au-S coordination bonds formed with all sulfur atoms of the reagent; the solvation number changes from 1 to 0.25 with increasing gold(III) aqueous concentration.
Extraction of gold(III), palladium(II), and platinum(IV) by 1-[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole from hydrochloric acid solutions
Khisamutdinov,Murinov,Shitikova
, p. 969 - 978 (2007)
The extraction of gold(III), palladium(II), and platinum(IV) with 1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole from hydrochloric acid solutions into toluene has been studied. The extraction follows the anion-exchange mec
Photooxidation of dicyanoaurate(I) induced by metal-to-ligand charge transfer excitation
Kunkely, Horst,Vogler, Arnd
, p. 853 - 855 (1998)
The irradiation of [Au(CN)2]- in oxygen-saturated acetonitrile leads to photooxidation of Au(I). In the presence of additional chloride [Au(CN)2Cl2]- is formed with φ = 0.5 × 10-4 at λ
Mixed valent gold oxides: Syntheses, structures, and properties of Rb5Au3O2, Rb7Au5O2, and Cs7Au5O2
Mudring, Anja-Verena,Nuss, Juergen,Wedig, Ulrich,Jansen, Martin
, p. 29 - 36 (2000)
The title compounds Rb5Au3O2, Rb7Au5O2, and Cs7Au5O2 are the first examples of mixed valent phases containing gold in the oxidation states +1 and -1. Their
Synthesis of: N-(3-aminopropyl)imidazole-based poly(ionic liquid) as an adsorbent for the selective recovery of Au(III) ions from aqueous solutions
Gui, Wenjun,Shi, Yun,Wei, Jia,Zhang, Zhifang,Li, Ping,Xu, Xia,Cui, Yanjun,Yang, Ying
, p. 20387 - 20395 (2020)
The synthesis of a novel poly(ionic liquid) adsorbent (PIL-APIBCl) through the modification of poly(styrene-co-maleic anhydride) (PSMA) composites with N-(3-aminopropyl)imidazole (API) and benzyl chloride (BCl) is presented. The structural analysis was carried out by nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FT-IR). Batch adsorption experiments revealed that the investigated adsorbent exhibited good selectivity and a high adsorption capacity of 236.68 mg g-1 towards tetrachloroaurate (Au(III)) ions at pH 1.0 over a wide temperature range. The adsorption isotherms and kinetics of Au(III) on the PIL-APIBCl were fitted well by the Langmuir isotherm model and pseudo-second-order model, respectively, indicating successful chemical adsorption of Au(III) ions on the adsorbent surfaces. According to FESEM, FT-IR, XPS and NMR analysis, the adsorption mechanisms of Au(III) on PIL-APIBCl could be ascribed to electrostatic and intermolecular interactions. Therefore, due to its good cyclability and low cost, PIL-APIBCl is a promising adsorbent for Au(III) recovery from wastewater on a large scale. This journal is
Ionic gold demonstrates antimicrobial activity against Pseudomonas aeruginosa strains due to cellular ultrastructure damage
Torres, Miguel Reyes,Slate, Anthony J.,Ryder, Steven F.,Akram, Maliha,Iruzubieta, Conrado Javier Carrascosa,Whitehead, Kathryn A.
, p. 3015 - 3024 (2021)
Due?to the ever-increasing rise of antimicrobial?resistant (AMR)?bacteria, the?development of?alternative antimicrobial agents is a global priority. The antimicrobial activity of ionic gold was explored against four Pseudomonas aeruginosa strains with different AMR profiles in order?to determine the antimicrobial activity of ionic gold and elucidate the mechanisms of action. Disc diffusion assays (zone of inhibition: ZoI) coupled with minimum inhibitory/bactericidal concentrations (MIC/MBC) were conducted to determine the antimicrobial efficacy of ionic gold. Scanning electron microscopy (SEM) was used to visualise morphological changes to the bacterial cell ultrastructure. Strains with increased AMR were slower to grow?which is likely a?fitness cost due to?the enhanced AMR activity. Although greater concentrations of ionic gold were required to promote antimicrobial activity, ionic gold demonstrated similar antimicrobial values?against all strains tested. Lowry assay results indicated that protein leakage was apparent following incubation with ionic gold, whilst SEM revealed?cellular ultrastructure damage. This study suggests that the application of ionic gold as an alternative antimicrobial?is promising, particularly against AMR P. aeruginosa. The antimicrobial activity of ionic gold against P. aeruginosa could potentially be utilised as an alternative therapeutic option in wound management, an approach that could benefit healthcare systems worldwide.
DISPLACEMENT BY CHLORIDE OF PYRIDINE-2-CARBOXYLATE FROM DICHLORO(PYRIDINE-2-CARBOXYLATO)GOLD(III) IN ACIDIC SOLUTION; THE POSITION OF RING OPENING
Annibale, Giuliano,Canovese, Luciano,Cattalini, Lucio,Marangoni, Giampaolo,Michelon, Gianni,Tobe, Martin L.
, p. 1641 - 1646 (1984)
The kinetics of the reaction + 2Cl- - + +HN-OH (where N-O = pyridine-2-carboxylate) have been studied at 25 deg C in methanol-water (95:5,v/v).In the presence of excess of chloride, the reaction involves a fast and reversible ring opening with Au-N bond breaking (K1 = 3.16 dm3 mol-1) and a reversible protonation of the free nitrogen (K2 = 640 dm3 mol-1, corresponding to a pKa of 2.80) followed by a typical associatively activated displacement of the O-bonded ligand by chloride, with the usual rate law, kobs. = k1 + k2-> where k1 (the solvolytic rate constant) = 1.9 1E-4 s-1 and k2 = 4.54 1E-2 dm3 mol-1 s-1.In the absence of chloride a solvolytic ring opening can be observed but the reaction stops before the monodentate ligand is displaced.
Ring opening and displacement by chloride of the bidentate chelate ligand from dichloro[pyridine-2-(α-methoxymethanolato)]gold(III) - A kinetic and mechanistic study
Marangoni, Giampaolo,Pitteri, Bruno,Annibale, Giuliano,Bortoluzzi, Marco
, p. 765 - 771 (2006)
The kinetics of ring opening and displacement of the bidentate chelate ligand from dichloro[pyridine-2-(α-methoxymethanolato)]gold(III) [Au(N-O)Cl2] (1) have been studied spectrophotometrically in methanol/water (95:5, v/v) at 25°C and constant ionic strength (I = 1 mol dm-3, LiClO4). In the presence of LiCl and perchloric acid the reaction consists of a pre-equilibrium protonation of the coordinated oxygen followed first by ring opening at oxygen accompanied by the entry of chloride or solvent and fast acetalisation of the hemiacetalic form of the ligand to give [AuCl3(N-OMe)], and then by displacement of the N-bonded ligand to give [AuCl4]-. The ligand is not displaced in the absence of chloride and no reaction is observed in the presence of chloride alone. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
