Formaldehyde Photodissociation: Molecular Beam, Product Appearance Rate, and Carbon-14 Isotopic Enrichment Studies
Year: 1981
Type: dissertation
Abstract: Several aspects of the formaldehyde photopredissociation mechanism were studied.The technique of crossed laser and molecular beams was used to study the system under ccllisionless conditions.Detection of the molecular product CO after excitation of H 2 CO near the S 1 origin gives strong support to the sequential decay model for fast nonradiative decay of S l states.For H 2 CO excitation at 283.9 nm, formation of the radical product HCO dominates dissociation to molecular products by an order of magnitude.CO appearance rates for H 2 CO excitation at 354.7, 317.0, 298.5 and 283.9 run were measured by time-resolved absorption of a CO laser, and were the same within -20%.These measurements could be complicated by rotational relaxation; an impulse approximation calculation using the CO translational energy distribution from the molecular beam experiment suggests that CO should be formed in high Jstates.The levidence for an intermediate in H 2CO photodissociation may thus be compromised.Simultaneous high resoluti.otspectra of li2 CO and H 2 :CO between 290 and 34.5 ntn were measured.About 30 linet with sttt eieTctiviti'es > 50 were Phôto1yses cn one stici .flneat 3269 nth .b:f a dilut-e
Author: P Shing Ho
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Awards: G1702950523, G660437508
OpenAlex ID: W2780283360