Jozef Hodyl PhD Thesis - Theses - Flinders University

lank containing the relevant solvent and buffer species. The guest solutions usedwere prepared immediately before use and were equilibrated at 298 K.Prior to performing each guest inclusion experiment, a calibration curve wasconstructed for the appropriate guest species. The general method for guest inclusionexperiments was to stir 10 cm 3 of the guest species at a concentration of 5 x 10 -3 moldm -3 in de-ionised water with 100 mg of the cadmium(II) complexed silica-basedreceptor material for 1 hour. The solid material was then isolated by filtration into avolumetric flask and washed with copious amounts of de-ionised water. Percentinclusion was determined by the difference between the initial concentration of theguest species and the concentration at equilibrium in the filtrate. For phenolates theprocedure was identical apart from the solvent which was 10% DMSO in acetonitrile(v/v).7.6 Diffuse reflectance infrared Fourier transform (DRIFT)spectroscopyThe silica-based materials were characterised by DRIFT spectroscopy as a finelyground KBr mixture in aluminium sample cups on either a Biorad FTS 40 A InfraredSpectrometer fitted with a Spectra-Tech 30-034 DRIFT accessory with an MCTdetector or a Nicolet Nexus 8700 FTIR Spectrophotometer fitted with a SmartCollector DRIFT accessory.7.7 Solid State 13 C CPMAS NMRSolid state nuclear magnetic resonance ( 13 C CPMAS NMR) spectra for the linkerattached and the combined receptor-linker attached silica materials were recorded atan operating frequency of 50.318 MHz on a Varian Unity 200 spectrometer using aDoty high speed probe in an open ended 7 mm zirconium oxide rotor with Kel-Fendcaps. The samples were spun at 5 kHz with a contact time of 1 ms and a recycle124