Deuteration Affects the Photodissociation of Formaldehyde Open Access

Abstract

Abstract Deuteration Affects the Photodissociation of Formaldehyde

By James Craig Shearouse The effect of mass in the phenomenon of formaldehyde roaming is investigated by the substitution of a single deuterium to determine whether the proton or the deuteron is more likely to roam. Possible issues with the preparation of the initial conditions for a physically accurate and meaningful quasiclassical trajectory simulation of formaldehyde photodissociation are explored in light of the proposed intramolecular relaxation mechanism, and a microcanonical sampling method is utilized. Additionally, an investigation is made as to whether the roaming phenomenon is associated with its own transition state or whether it is, as hypothesized, a barrierless process. The results of quasiclassical trajectory simulation of the deuterated system are compared to the predictions made by a phase space theory/RRKM theory prediction of product distributions.

Table of Contents

Table of Contents

1. Introduction pg. 1 2. Phase Space/RRKM Theory Predictions pg. 4 3. Quasiclassical Trajectory Simulation pg. 9 4. Detecting Roaming pg. 12 5. Stationary Point Search pg. 16 6. Results and Discussion pg. 18 7. Conclusions pg. 21 List of Figures Fig. 1 Lifetimes of all Trajectories Starting from "Stretched Formaldehyde" pg. 26 Fig. 2 Lifetimes of H+HCO Trajectories Starting from "Stretched Formaldehyde" pg. 27 Fig. 3 Lifetimes of H2+CO Trajectories Starting from "Stretched Formaldehyde" pg. 28 Fig. 4 HD Vibrational Distribution from 37000 cm-1 Photodissociation pg. 29 Fig. 5 H2 Vibrational Distribution from 37000 cm-1 Photodissociation pg. 30 Fig. 6 C-H Bond Length during a Roaming D Trajectory, Example 1 pg. 31 Fig. 7 C-D Bond Length during a Roaming D Trajectory, Example 1 pg. 32 Fig. 8 C-H Bond Length during a Roaming D Trajectory, Example 2 pg. 33 Fig. 9 C-D Bond Length during a Roaming D Trajectory, Example 2 pg. 34 Fig. 10 Comparison of H2 and HD Vibrational Distributions pg. 35 Fig. 11 Comparison of CO Vibrational Distributions from H2CO and HDCO pg. 36

About this Dissertation

Rights statement

• Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.

School	Laney Graduate School
Department	Chemistry
Degree	MS
Submission	Dissertation
Language	English
Research Field	Chemistry, Physical
Keyword	Photodissociation Molecular Dynamics Quasiclassical Trajectory Roaming
Committee Chair / Thesis Advisor	Bowman, Joel M, Emory University
Committee Members	Heaven, Michael, Emory University Kindt, James, Emory University

Last modified

Primary PDF

Thumbnail	Title	Date Uploaded	Actions
	Deuteration Affects the Photodissociation of Formaldehyde ()	2018-08-28 13:04:49 -0400	Press to Select an action Download

Supplemental Files

Thumbnail	Title	Date Uploaded	Actions