Wavelength-Dependent Photolysis of C3-C7 Aldehydes in the 280–330 nm Region

Abstract

ABSTRACT This article reviews the work over the past few years on the photolysis of propionaldehyde, n-butyraldehyde, n-pentanal, n-hexanal, and n-heptanal in the 280–330 nm region, obtained by combining laser photolysis with cavity ring-down spectroscopy. Absorption cross-sections of these aldehydes were measured. The HCO radical was observed as a photodissociation product. The HCO quantum yield was determined as a function of photolysis wavelength, aldehyde pressure, and nitrogen buffer-gas pressure. A scheme to group aldehydes according to similarity in photochemistry was proposed. KEYWORDS: absorption cross sectionsaldehydescavity ring-down spectroscopyphotodissociation rate and lifetimephotolysisradical quantum yields ACKNOWLEDGMENTS We are grateful for the support provided by the National Science Foundation (grants ATM-9610285, ATM-0000252, and ATM-0300294). We thank Dr. Adriana Verschoor for critical readings of the manuscript, and two reviewers for helpful suggestions. Notes a Cross-section data for propionaldehyde were taken from reference 19. b Cross-section data for n-butyraldehyde were taken from reference 20. c Cross-section data for n-pentanal were taken from reference 21. d Cross-section data for n-hexanal were taken from reference 22. e Cross-section data for n-heptanal were taken from reference 22. a Quantum yield values for propionaldehyde were taken from reference 19. b Quantum yield values for n-butyraldehyde were taken from reference 20. c Quantum yield values for n-pentanal were taken from reference 21. d Quantum yield values for n-hexanal were taken from reference 22. e Quantum yield values for n-heptanal were taken from reference 22.