Laser spectroscopic studies in molecular beams, clusters and at liquid interfaces
Laser spectroscopic studies in molecular beams, clusters and at liquid interfaces
The photodissociation dynamics of HOC1 and DOC1 at 266 nm have been investigated using an effusive molecular beam and pump-probe laser techniques to obtain the nascent internal state distibutions of the OH/OD radicals using laser excitation fluorescence. The OH fragments are found to possess little rotational or vibrational energy but have considerable translational energy. Gaussian rotational state population distibutions are observed which are consistent with a theoretical model for the photodissociation that states that OH fragment rotation arises from HOC1 zero-point bending motions. The degree of rotational excitation is greater for DOC1 than for HOC1 which is explained by considering the limitations fo the theoretical model. The relative populations of the OH spin-orbit states suggests that there may be some correlation between the states of the OH and Cl fragments. The alignment parameter, β02(02), is found to be negative (-0.3) and it is suggested that the dissociation occurs in the HOC1 rotational plane and primarily through the 21A' electronic state. A `magic' angle is established for the polarization direction of the photolysis laser relative to the probe laser allowing the acquisition of alignment-free data.
The collisional quenching by methane molecules of electronically excited Ba(1P1) attached to large van der Waals clusters of argon has been investigated using the crossed molecular beam technique. The quenching rate is described by first order kinetics and is found to be inversely proportional to the cluster surface area. Diffusion coefficients are evaluated and are found to be inconsistent with previous structural studies of argon clusters. Comparisons are made between reactions occurring within clusters and micelles.
University of Southampton
1993
Hickman, Christopher Guy
(1993)
Laser spectroscopic studies in molecular beams, clusters and at liquid interfaces.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The photodissociation dynamics of HOC1 and DOC1 at 266 nm have been investigated using an effusive molecular beam and pump-probe laser techniques to obtain the nascent internal state distibutions of the OH/OD radicals using laser excitation fluorescence. The OH fragments are found to possess little rotational or vibrational energy but have considerable translational energy. Gaussian rotational state population distibutions are observed which are consistent with a theoretical model for the photodissociation that states that OH fragment rotation arises from HOC1 zero-point bending motions. The degree of rotational excitation is greater for DOC1 than for HOC1 which is explained by considering the limitations fo the theoretical model. The relative populations of the OH spin-orbit states suggests that there may be some correlation between the states of the OH and Cl fragments. The alignment parameter, β02(02), is found to be negative (-0.3) and it is suggested that the dissociation occurs in the HOC1 rotational plane and primarily through the 21A' electronic state. A `magic' angle is established for the polarization direction of the photolysis laser relative to the probe laser allowing the acquisition of alignment-free data.
The collisional quenching by methane molecules of electronically excited Ba(1P1) attached to large van der Waals clusters of argon has been investigated using the crossed molecular beam technique. The quenching rate is described by first order kinetics and is found to be inversely proportional to the cluster surface area. Diffusion coefficients are evaluated and are found to be inconsistent with previous structural studies of argon clusters. Comparisons are made between reactions occurring within clusters and micelles.
This record has no associated files available for download.
More information
Published date: 1993
Identifiers
Local EPrints ID: 462332
URI: http://eprints.soton.ac.uk/id/eprint/462332
PURE UUID: e1eacaa0-d1a2-462f-af24-8c32284d82cd
Catalogue record
Date deposited: 04 Jul 2022 19:05
Last modified: 04 Jul 2022 19:05
Export record
Contributors
Author:
Christopher Guy Hickman
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics