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Probing Base Metal Coordination Complexes Using Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry

Presently, much research has been completed focusing on metal coordination complexes in the liquid phase but very little in terms of the gas phase. The purpose of this research is to further investigate these conditions and learn more about the reactions that can occur using Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry (ESI QToF MS). This research focuses on Nickel (II) and Iron (III) Nitrate solutions in combination with five ligands: 2,2’-Bipyridine, 4,4’-Bipyridine, 2,2’-Bipyridine-4,4’-Dicarboxylic Acid, 1,10-Phenanthroline and the Baker Group’s SNS Ligand. Observations of these complexes were restricted to the monocations. Those combinations that successfully coordinated in the gas phase were subjected to further analysis to determine their fragmentation pathways under specific conditions. To investigate their interactions, studies were conducted using three different mixing techniques. These techniques included a pre-mixed single-spray solution, a dual-spray injection method, and the TRESI (time-resolved electrospray ionization) method. By using all three methods, the compounds’ ability to react in solution over time can be compared to real-time mixing in both the gas and liquid phases, via dual-spray and TRESI techniques respectively. Further experimentation took place on target complexes, created by each of the ten combinations of starting compounds, to further investigate the gas phase properties and fragmentation patterns that exist. It was observed that most experiments with the Nickel (II) Nitrate solution were successful with all three methods, while the Iron (III) Nitrate however created some problems. In general, single-spray analysis gave the best results compared to dual-spray, which was ineffective for some combinations, particularly the 2,2’-Bipyridine-4,4’-Dicarboxylic Acid and SNS ligands. It was found that both the 2,2’-Bipyridine and 4,4’-Bipyrdine combinations produced very similar results despite their respective bidentate and bridging coordination tendencies. The TRESI method provided limited information due to the delayed reaction times with some combinations. Overall, this work proved useful in its ability to compare metal coordination complex formation in solution and gas phases.

Identiferoai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/43244
Date03 February 2022
CreatorsMartin, Jessica J.
ContributorsBaker, R. Tom
PublisherUniversité d'Ottawa / University of Ottawa
Source SetsUniversité d’Ottawa
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Formatapplication/pdf

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