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Electrospray ionization mass spectrometry (ESI-MS) has been applied to the real time study of air-sensitive homogenous organometallic catalytic reactions due to its soft ionization properties. Therefore, fragile molecules and complexes in these reactions were characterized. The kinetic studies of these reactions have also been done by following the relative abundance of different species including starting material(s), products, by-product(s) as well as intermediates. Based on the results, reaction pathways and mechanisms were proposed and numerical models were built to accurately mimic the reactions under specific condition. In order to make the reactions detectable by ESI-MS, many charged ESI-MS friendly substrates were synthesized as tracking tags, including 1-allyl-1-(prop-2-yn-1-yl)piperidin-1-ium hexafluorophosphate(V), 1-allyl-1-(prop-2-yn-1-yl)pyrrolidin-1-ium hexafluorophosphate(V), (4-ethynylbenzyl)triphenylphosphonium hexafluorophosphate(V), hex-5-yn-1-yltriphenylphosphonium hexafluorophosphate(V) etc. The method for continuously monitoring water- and oxygen-sensitive reactions in real time named pressurized sample infusion (PSI) was developed, optimized and applied throughout all the projects in the thesis. These techniques were applied to detailed studies of the intramolecular Pauson-Khand reaction (PKR) with Co2CO8 under different temperatures. The kinetic study results gave the entropy and enthalpy of the reaction and evidence suggested that the ligand dissociation step was the rate-determining step of the reaction. Hydrogenation of alkynes with Wilkinson’s catalyst and Weller’s catalyst were also studied using PSI. The behaviour of starting materials and products were tracked, then various reactions were carried out by using different temperatures and concentrations. Furthermore, competition reaction and kinetic isotope effect study, mechanisms were proposed based on experimental results, numerical models were built, and rate constants for each step were estimated. Different Si-H activation reactions were studied including hydrolysis of silanes, hydrosilation, dehydrocoupling of silanes, alcoholysis of silane and silane redistribution by using (3-(methylsilyl)propyl)triphenylphosphonium hexafluorophosphate(V). A variety of collaborative projects were also carried out including hydroacylation, fast-activating Pd catalyst precursor, catalyst analysis for Cu-mediated fluorination, CdSe - NiDHLA analysis, Ru catalyzed propargylic amination reaction, Zn catalyzed lactide polymerization, and Fe4S4 clusters. / Graduate / jingwei@uvic.ca

Universiẗat, Diss.--Münster, 1999.

Chemnitz-Zwickau, Techn. Univ., Diplomarb., 1994.

Universiẗat, Diss., 2003--Würzburg. / Erscheinungsjahr an der Haupttitelstelle: 2002.

The glycosylation features of CSF oligoclonal IgG, and possible changes in N-glycans of CSF IgG in multiple sclerosis (MS) were studied. After isoelectric focusing (IEF) of CSF, bands were detected using biotinylated lectins and avidin-horseradish peroxidase. Concanavalin A (Con A) binding showed that mannose exists throughout the pH range of oligoclonal IgG. Sambucus nigra antigen (SNA) bound acidic and neutral oligoclonal IgG only, suggesting that alkaline oligoclonal IgG is deficient in sialic acid. Deglycosylation of CSF IgG using peptide-N-glycosidase F suggested that the range of isoelectric points of oligoclonal IgG bands is not due to carbohydrate differences alone. Lectin immunoassays, whereby protein A purified IgG was captured by anti-IgG coated tubes and probed using a range of biotinylated lectins, were used to compare 13 CSF samples from MS patients with 14 control samples. With Con A binding, a significantly higher mean and larger variance was found for the MS group (t-test: P < 0.05). Con A binding correlated with CSF [IgG]/[total protein]% (r=0.390; P=0.0443). Using HPLC to separate oligosaccharides released from IgG by hydrazinolysis and labelled with 2-aminobenzamide, glycans were determined in 7 CSF samples with oligoclonal IgG, and 6 CSF samples without. The ratio of the peak for biantennary fucosylated agalactosyl glycans to total monogalactosylated glycan peaks was lower for the oligoclonal IgG samples (t-test: P=0.0141). The overall results suggested that glycosylation changes occur in CSF IgG in MS, and that oligoclonal IgG contains less sialic acid but more galactose than polyclonal IgG.

No description available.

No description available.