NMR Characterization of Ligand Binding and Exchange Dynamics in Triphenylphosphine-Capped Gold Nanoparticles

Abstract

An ultraviolet-visible (UV-Vis) absorption spectrum was collected on a solution of PPh 3 capped 1.8 nm AuNPs dissolved in CH 2 Cl 2 (0.5 mg/ml) using an Ocean Optics Instrument. A UV-Vis spectrum is shown in figure S1. The amplitude and position of the plasmon band can be used as a guideline to predict the nanoparticle core size. UV-Vis absorption spectrum shown in figure S1 does not show any significant plasmon resonance around 520 nm, which indicates that the majority of the sampled nanoparticles are < 2.0 nm in diameter. 1 This result is consistent with statistical data derived from TEM images of the nanoparticles (Figure 1). TGA Thermal gravimetric analysis (TGA) of the nanoparticles was performed (SETARAM Instrument) to measure the mass associated with surface bound PPh 3 and gold core, respectively. The temperature was raised from room temperature to reach 600 o C at a rate of 10 o C/min under a helium atmosphere. At the end of the experiment, the remaining gold from the sample of nanoparticles was recovered from the alumina sample holder. The TGA data reported in figure S2 shows that the surface S1. UV-Vis absorption spectrum of PPh 3 capped gold nanoparticles dissolved in CH 2 Cl 2 .S2. TGA analysis of PPh 3 capped 1.8 nm AuNPs. A loss of 23% mass occurred when the sample was heated > 400 o C.

Functionalization of small platinum nanoparticles with amines and phosphines: Ligand binding modes and particle stability

“…The signals at 58 ppm and 32 ppm are in good agreement with the spectra described for triphenylphosphine-stabilized gold nanoparticles in the literature, while the resonance at 2 ppm has not yet been reported for such systems (see Supporting Information Fig. S17) [41][42][43].…”

Tetrapropylammonium Occlusion in Nanoaggregates of Precursor of Silicalite-1 Zeolite Studied by 1H and 13C NMR

“…Although particles are supposed to exhibit solid-state characteristics at a microscopic scale with some softness and flexibility, liquid-state NMR instrumentation enables their measurement in reasonable conditions. In general, theoretical and experimental approaches usually applied for either liquids or solids may be extended to dispersed nanoparticles as well [43][44][45][46][47][48][49]. While a liquid or dissolved component in solution will preserve its full diffusive mobility depending on the overall viscosity, any constituent of the solid structure of the particle will be more or less immobilized within the solid network.…”

Au nanoparticles stabilised by PEGylated low generation PAMAM dendrimers: Design, characterisation and properties

“…by NMR techniques) compared to other applied dendrimers [14,20,21]. Furthermore, our biocompatible organic coatings are also more effective than monodentate stabilisers such as triphenylphosphine [31] or alkanethioles [32], as they provide more donating functionalities per gram. Bearing up to ten tentacles, the molecules described here act as promising templates in the formation of Au NPs using H[AuCl 4 ] as gold source and Na [BH 4 ] as reducing agent.…”