A measurement of the photoionization cross section of CH2Cl via photofragment translational spectroscopy of dichloromethane

• Published in: Chemical physics letters Vol. 687; pp. 284 - 289
• Main Authors: Scrape, Preston G., Xu, Rosalind J., Adams, Jonathan D., Lee, Shih-Huang, Butler, Laurie J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2017
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2017.09.027

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•The photoionization cross section of the CH2Cl radical is determined.•Four photodissociation channels of CH2Cl2 at 157nm are identified.•The HCl photoelimination channel has a trimodal recoil kinetic energy distribution.
We characterize the 157nm photodissociation of dichloromethane (CH2Cl2) using photofragment translational spectroscopy, detecting the products with photoionization mass spectrometry. The major photodissociation products are Cl+CH2Cl and HCl+CHCl. Comparing the integrated ion signal at m/e=35 (Cl+) and m/e=49 (CH2Cl+) gives the partial photoionization cross section of CH2Cl to parent ion to be σ=26.6Mb at 13.7eV. This value is a quantitative anchor point of the energy-dependent photoionization cross section. In recent work we used this result to quantify the product branching to HCO+CH2Cl in the photodissociation of 2-chloroacetaldehyde.