Adelaide Graduate Centre publications

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Browsing Adelaide Graduate Centre publications by Author "Bos, R."

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    Characterisation of a synthesised fluorescent ligand (4-acridinol-1-sulphonic acid) using nuclear magnetic resonance spectroscopy
    (Elsevier Science BV, 2002) Bos, R.; Barnett, N.; Dyson, G.; Russell, R.
    The synthesis and complete characterisation of the fluorescent ligand, 4-acridinol-1-sulphonic acid (the acridine analogue of 8-quinolinol-5-sulfonic acid) is described. Using a judicious array of nuclear magnetic resonance spectroscopy experiments, the structural elucidation and full assignment of all proton and carbon chemical shifts were afforded. The 4-acridinol-1-sulphonic acid was found to behave in a similar manner to 8-quinolinol-5-sulphonic acid, forming fluorescent complexes with magnesium(II) and zinc(II). The uncorrected emission maxima for the metal–acridinol complexes were found to be at around 620 nm compared to 505 nm for the respective quinolinol complexes. Unfortunately, preliminary spectrofluorimetric analytical figures of merit revealed that the detection limits of the new acridinol metal complexes were one and a half orders of magnitude poorer than those attained with the corresponding quinolinol ligand. However, in contrast to 8-quinolinol-5-sulphonic acid, the 4-acridinol-1-sulphonic acid ligand showed considerable selectivity for magnesium(II) and zinc(II) over aluminium(III).
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    Studies on the mechanism of the peroxyoxalate chemiluminescence reaction - Part 2. Further identification of intermediates using 2D EXSY C-13 nuclear magnetic resonance spectroscopy
    (Elsevier Science BV, 2008) Tonkin, S.; Bos, R.; Dyson, G.; Lim, K.; Russell, R.; Watson, S.; Hindson, C.; Barnett, N.
    Further consideration has been given to the reaction pathway of a model peroxyoxalate chemiluminescence system. Again utilising doubly labelled oxalyl chloride and anhydrous hydrogen peroxide, 2D EXSY (13)C nuclear magnetic resonance (NMR) spectroscopy experiments allowed for the characterisation of unknown products and key intermediate species on the dark side of the peroxyoxalate chemiluminescence reaction. Exchange spectroscopy afforded elucidation of a scheme comprised of two distinct mechanistic pathways, one of which contributes to chemiluminescence. (13)C NMR experiments carried out at varied reagent molar ratios demonstrated that excess amounts of hydrogen peroxide favoured formation of 1,2-dioxetanedione: the intermediate that, upon thermolysis, has been long thought to interact with a fluorophore to produce light.
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    Studies on the mechanism of the peroxyoxalate chemiluminescence reaction Part 1. Confirmation of 1 2-dioxetanedione as an intermediate using 13C nuclear magnetic resonance spectroscopy
    (Elsevier Science BV, 2004) Bos, R.; Barnett, N.; Dyson, G.; Lim, K.; Russell, R.; Watson, S.
    A simple model peroxyoxalate chemiluminescence system was monitored directly across a range of temperatures (from −80 to +20 °C) using 13C nuclear magnetic resonance spectroscopy. These experiments were made possible by the utilisation of 13C doubly labelled oxalyl chloride, which was reacted with anhydrous hydrogen peroxide in dry tetrahydrofuran. Ab initio quantum calculations were also performed to estimate the 13C nuclear magnetic resonance (NMR) shift of the most commonly postulated key intermediate 1,2-dioxetanedione and this data, in concert with the spectroscopic evidence, confirmed its presence during the reaction.
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    Synthesis and preliminary analytical evaluation of the chemiluminescence from (4-[4-(dichloromethylsilanyl)-butyl]-4'-methyl-2 2'-bipyridyl)bis(2 2'-bipyridyl))ruthenium(II) covalently bonded to silica particles
    (Royal Soc Chemistry, 2002) Barnett, N.; Bos, R.; Brand, H.; Jones, P.; Lim, K.; Purcell, S.; Russell, R.
    This paper describes, for the first time, a simple and effective synthetic route for covalently bonding the chemiluminescence reagent, (4-[4-(dichloromethylsilanyl)-butyl]-4-methyl-2,2-bipyridyl)bis(2,2-bipyridyl)ruthenium(II) onto silica particles. The subsequent preparation of chemically regeneratable detection cells and their preliminary analytical evaluation with both sequential injection analysis and flow injection analysis are also reported. Unoptimised analytical figures of merit were established for standard solutions of codeine and sodium oxalate with detection limits calculated from three times the standard deviation of the blank signal, of 1 × 10–8 M and 3 × 10–7 M respectively. The chemically immobilised reagent exhibited some intriguing solvent and kinetic effects, which are also briefly discussed.