Redispersion of transition metal nanoparticle catalysts in tetraalkylphosphonium ionic liquids

Abhinandan Banerjee, Robin Theron, Robert W. J. Scott
2013 Chemical Communications  
Experimental Materials: Commercially available reagents (such as metal precursors from Sigma Aldrich) were used without purification unless noted otherwise. High purity solvents were purchased from Fischer Scientific and 100% ethanol was purchased from Commercial Alcohols. 18MΩ cm Milli-Q (Millipore, Bedford, MA) was used throughout. Ionic liquids were donated by Cytec Canada, and were used after drying under the vacuum at 60 0 C for 8 hours. General Comments on Techniques: Unless otherwise
more » ... ed, all reactions were performed using standard Schlenk techniques, with nitrogen to provide an inert atmosphere, in oven-dried Schlenk glassware. 1 H and 13 C-NMR spectra were recorded at 500 MHz on a Brüker Avance spectrometer. NMR spectra were recorded in deuterated chloroform (CDCl 3 ) solutions, with residual chloroform (δ = 7.27 ppm for 1 H NMR and δ = 77.23 ppm for 13 C-NMR) taken as the internal standard, and were reported in parts per million (ppm). For ambient temperature UV/Vis spectra, a Varian Cary 50 Bio UV/Visible spectrophotometer with a scan range of λ=200-800 nm and quartz cuvettes with optical path lengths of 0.4 cm were used. A Cary 6000i spectrophotometer, equipped with a sample changer and a constant temperature bath capable of holding cuvettes and stirring their contents with the aid of a magnetic stirrer while recording their spectra, was used for the etching studies. To avoid effects of oxygen depletion on etching of NPs, the contents of the cuvettes were flushed with oxygen between readings. TEM analyses of the NPs in different ILs were conducted by using a Philips 410 TEM operating at 100 kV. The TEM samples were prepared by ultrasonication of ~5% solution of the NP/IL solution in CHCl 3 followed by drop-wise addition onto a carbon-coated copper TEM grid (Electron Microscopy Sciences, Hatfield, PA). To determine particle diameters, a minimum of 100 particles from each sample from several TEM images were manually measured by using the ImageJ program. For Electronic Supplementary Material (ESI) for Chemical Communications This journal is
doi:10.1039/c3cc40726h pmid:23482965 fatcat:wpzbjsbqsbh6vki64e3ijpq5b4