The aim of this thesis was the experimental investigation of fundamental, gas phase, bimolecular chemical processes, using laser methods for the state-selective preparation of reagents and for the state-specific detection of nascent products. An apparatus was developed which allowed the state-specific spectroscopic detection of gas phase molecules by either laser-induced fluorescence (LIF) or resonance-enhanced-multiphoton-ionisation (REMPI). The apparatus incorporates time-of-flight (TOF) mass discrimination of ions produced in the REMPI process. A spectroscopic investigation was performed to establish whether LIF or REMPI was the optimum detection method for the OH radical. Our preliminary conclusion was that LIF remained the optimum method for the detection of OH. The dynamics of elementary O(<SUP>3</SUP>P) atoms + saturated hydrocarbon reactions have been investigated experimentally. Reaction was initiated by pulsed laser photolysis of NO<SUB>2</SUB> precursor molecules to produce reactive O(<SUP>3</SUP>P) atoms with a characteristic distribution of recoil velocities. These atoms collide and react with saturated hydrocarbon molecules chosen to contain representative primary, secondary and tertiary C-H bonds, respectively. The nascent OH(X<SUP>2</SUP>II) product was detected in a state-specific fashion by LIF. The partitioning of the available energy among vibrational, rotational and fine-structure states of the products has been determined. The (2+1) REMPI spectroscopy of HC1 was investigated to determine which transitions would be suitable for the measurement of ground state rovibrational populations of nascent HC1 produced in a chemical process. Certain vibronic bands of the <I>V</I><SUP>1</SUP>Σ<SUP>+</SUP> → <I>X</I><SUP>1</SUP>Σ<SUP>+</SUP> transition were found to be sufficiently unperturbed to be suitable candidates for population studies.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:663517 |
| Date | January 1994 |
| Creators | Watson, Allister |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14642 |
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