Examination of the Orientation of the Angular Momentum of the NO Photofragment from the 280 nm. Photodissociation of Methyl Nitrite Using Circularly Polarized Light
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Authors
Klobuchar, Aidan James
Issue Date
2011
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Methyl nitrite is a highly studied molecule for investigation of the photodissociation dynamics of a bent system. While our lab has previously studied
the vector correlations in the 225 nm photodissociation of CH3ONO, reveal-
ing the alignment of the j, v and vectors, the orientation of these vectors
has not yet been measured. The goal of the investigation was to discover
the orientation of the j vector to determine whether the O-N-O bond angle
increased or decreased during the dissociation event using the 2
0(21) odd
bipolar moment. A three color photodissociation and 1 + 10 REMPI scheme
was used for photodissociation and ionization: 280 nm linearly polarized
light for dissociation of CH3ONO, a tunable 223 - 226 nm circularly polar-
ized beam to probe the NO, and a 308 nm beam for ionizing excited NO.
The NO+ product ions were detected by photofragment ion imaging. The
ion images were analyzed in order to determine the value of the 2
0(21) odd
bipolar moment. For P and R branch transitions, the ion images showed a
qualitative dependence on the helicity of the circularly polarized light and
produced average values of 2
0(21) of 0:40 and 0:23 for P and R (P11 and
Q21 + R11) branches respectively. As expected, the Q branches showed no
signi cant dependence on the helicity of the probe light. This indicates that
the O-N-O bond angle increases on the excited surface. This is in contrast
to NO2, which has been shown to have the O-N-O bond angle decrease as
the dissociation event unfolds.
Description
viii, 44 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder. All rights reserved.