Gas Phase Molecular Spectroscopy: Electronic Spectroscopy of Combustion Intermediates, Chlorine Azide Kinetics, and Rovibrational Energy Transfer in Acetylene Público
Freel, Keith Allen (2013)
Abstract
This dissertation is composed of three sections. The first deals with the electronic spectroscopy of combustion intermediates that are related to the formation of polycyclic aromatic hydrocarbons. Absorption spectra for phenyl, phenoxy, benzyl, and phenyl peroxy radicals were recorded using the technique of cavity ring-down spectroscopy. When possible, molecular constants, vibrational frequencies, and excited state lifetimes for these radicals were derived from these data. The results were supported by theoretical predictions.
The second section presents a study of electron attachment to chlorine azide (ClN3) using a flowing-afterglow Langmuir-probe apparatus. Electron attachment rates were measured to be 3.5x10−8 and 4.5x10−8 cm3s−1 at 298 and 400 K respectively. The reactions of ClN3 with eighteen cations and seventeen anions were characterized. Rate constants were measured using a selected ion flow tube. The ionization energy (>9.6eV), proton affinity (713±41 kJ mol−1), and electron affinity (2.48±0.2 eV) for ClN3 were determined from these data.
The third section demonstrates the use of double resonance spectroscopy to observe state-selected rovibrational energy transfer from the first overtone asymmetric stretch of acetylene. The total population removal rate constants from various rotational levels of the (1,0,1,00,00) vibrational state were determined to be in the range of (9-17) x 10-10 cm3s-1. Rotational energy transfer accounted for approximately 90% of the total removal rate from each state. Therefore, the upper limit of vibrational energy transfer from the (1,0,1,00,00) state was 10%.Table of Contents
Section 1: Cavity Ring-down Spectroscopy of Polycyclic Aromatic
Hydrocarbon Transient Species........................................................................ 1Chapter 1. Introduction to Spectroscopy of Combustion Intermediates.... 1
Bibliography....................................................................................... 12Chapter 2. Development and Theory of Cavity Ring-down Spectroscopy 15
Bibliography....................................................................................... 21Chapter 3. Experimental.......................................................................... 22
3.1. Cavity Ring-down Spectrometer.................................................. 24
3.2. Electrical Discharge Assembly.................................................... 26
3.3. Gas Expansion and Cooling........................................................ 303.4. LabVIEW Programs.................................................................... 33
Bibliography....................................................................................... 36
Chapter 4. Experimental Optimization.................................................... 374.1. Iodine.......................................................................................... 38
4.1.1. Introduction....................................................................... 38 4.1.2. Experimental...................................................................... 39 4.1.3. Results and Discussion....................................................... 40 4.2. C2................................................................................................ 44 4.2.1. Introduction....................................................................... 44 4.2.2. Experimental...................................................................... 45 4.2.3. Results and Discussion....................................................... 46 4.3. C6H............................................................................................ 48 4.3.1. Introduction....................................................................... 48 4.3.2. Experimental...................................................................... 49 4.3.3. Results and Discussion....................................................... 49 4.4. N2+............................................................................................. 52 4.4.1. Introduction....................................................................... 52 4.4.2. Experimental...................................................................... 52 4.4.3. Results and Discussion....................................................... 53 4.5. Redesign of the Valve System.................................................... 56 4.5.1. Introduction....................................................................... 56 4.5.2. Experimental...................................................................... 57 4.5.3. Results and Discussion....................................................... 58 4.6. Dissociation by Pyrolysis............................................................ 59 4.6.1. Introduction....................................................................... 59 4.6.2. Experimental...................................................................... 614.6.3. Results and Discussion ...................................................... 62
Bibliography....................................................................................... 68 Chapter 5. The Phenyl Radical................................................................. 705.1. Introduction................................................................................ 70
5.2. Experimental............................................................................... 735.3. Experimental Results.................................................................. 75
5.4. Theoretical Calculations and Analysis......................................... 80
5.5. Discussion and Conclusions........................................................ 92 Bibliography....................................................................................... 95 Chapter 6. The Phenoxy Radical.............................................................. 976.1. Introduction................................................................................ 97
6.2. Experimental............................................................................... 996.3. Experimental Results................................................................ 101
6.4. Theoretical Calculations and Analysis....................................... 103
6.5. Discussion and Conclusions...................................................... 115 Bibliography..................................................................................... 120Chapter 7. The Phenylperoxy Radical.................................................... 123
7.1. Introduction.............................................................................. 123
7.2. Experimental............................................................................. 1277.3. Experimental Results................................................................ 129
7.4. Theoretical Calculations............................................................ 135
7.5. Discussion................................................................................. 144 Bibliography..................................................................................... 150Section 2: Chlorine Azide - Electron Attachment and Reactions with
Ions At the Air Force Research Laboratory.................................................. 152
Chapter 8. Electron Attachment to Chlorine Azide............................... 152
8.1. Introduction.............................................................................. 152
8.2. Experimental............................................................................. 1558.3. Results and Discussion.............................................................. 159
8.4. Conclusions............................................................................... 165
Bibliography..................................................................................... 166
Chapter 9. Reactions of Positive and Negative Ions with ClN3 at 300K 168
9.1. Introduction.............................................................................. 168
9.2. Experimental............................................................................. 1699.3. Results: ClN3 + Negative Ions.................................................. 171
9.3.1. Negative Ions + Cl2......................................................... 173 9.3.2. Negative Ions + ClN3...................................................... 1759.4. Discussion: ClN3 + Negative Ions............................................ 178
9.5. Results: ClN3 + Positive Ions................................................... 181
9.6. Discussion: ClN3 + Positive Ions.............................................. 185
Bibliography..................................................................................... 187
Section 3: Rovibrational Energy Transfer in Acetylene................................ 189
Chapter 10. Rotational and Vibrational Energy Transfer From the
First Overtone Stretch (10100)00 of Acetylene..................................... 189
10.1. Introduction............................................................................ 189
10.2. Experimental........................................................................... 193
10.2.1. Double Resonance Spectroscopy................................... 193
10.2.2. Experimental Setup........................................................ 19510.3. Results and Analysis................................................................ 198
10.3.1. Absorption Spectrum of Acetylene................................ 198
10.3.2. Probe Scan Results and Analysis.................................... 199
10.3.3. Pump Scan Results and Analysis.................................... 202
10.3.4. Time Delay Scan Results and Analysis........................... 207
10.3.5. Quantitative Analysis of Energy Transfer...................... 208
10.3.6. Scaling Law.................................................................... 212 10.3.7. Vibrational Energy Transfer........................................... 21410.4. Discussion and Conclusions..................................................... 214
Bibliography...................................................................................... 217
About this Dissertation
School | |
---|---|
Department | |
Degree | |
Submission | |
Language |
|
Research Field | |
Palavra-chave | |
Committee Chair / Thesis Advisor | |
Committee Members |
Primary PDF
Thumbnail | Title | Date Uploaded | Actions |
---|---|---|---|
Gas Phase Molecular Spectroscopy: Electronic Spectroscopy of Combustion Intermediates, Chlorine Azide Kinetics, and Rovibrational Energy Transfer in Acetylene () | 2018-08-28 13:44:27 -0400 |
|
Supplemental Files
Thumbnail | Title | Date Uploaded | Actions |
---|