PHOTODISSOCIATION OF FORMIC ACID ISOLATED IN SOLID PARAHYDROGEN

Loading...
Thumbnail Image

Date

2011

Journal Title

Journal ISSN

Volume Title

Publisher

Ohio State University

Research Projects

Organizational Units

Journal Issue

Abstract

The \textit{in situ} photochemistry of dopant molecules isolated in solid parahydrogen (pH$_2$) typically differs from analogous studies in rare gas crystals for two main reasons: (1) solid pH$_2$ has a negligible cage effect so that photodissociation of a precursor molecule can lead efficiently to well-separated fragments, and (2) radical fragments can potentially react with the pH$_2$ matrix. Our group is currently studying the 193 nm photochemistry of a number of precursor molecules isolated in solid pH$_2$ via high-resolution FTIR spectroscopy. In this talk I will present results for the 193 nm photolysis of formic acid (FA) in solid pH$_2$. In rare gas matrices, the analogous FA photochemistry proceeds via the CO+H$_2$O and CO$_2$+H$_2$ photodissociation channels.$s$\ddot{a}$nen, \textit{J. Mol. Struct. }\textbf{436-437}, 349 (1997).} In solid pH$_2$, in addition to these channels we observe the production of HCO and HOCO. Further, after the UV laser is turned off, the HOCO concentration continues to increase with a slow first-order rate constant for a period of 10 hours. At this point, we still do not have a full explanation of the chemical mechanism leading to the post-photolysis increase in the HOCO concentration.

Description

Author Institution: Department of Chemistry, University of Wyoming, Laramie, WY 82071-3838

Keywords

Citation