Infrared spectroscopy and 193 nm photochemistry of methylamine isolated in solid parahydrogen
Fredrick M Mutunga1, David T Anderson1
1Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States.
Abstract:
The in situ UV photolysis of a precursor molecule trapped in a parahydrogen (pH2) matrix is a simple method used to generate isolated radical photofragments that are well suited for infrared spectroscopic studies. However, for molecules that can dissociate via multiple pathways, little is known about how the pH2 matrix influences the branching among these open pathways. We report FTIR spectroscopic studies of the 193 nm photodecomposition of methylamine (MA, CH3NH2) isolated in pH2 quantum matrixes at 1.8 K. We observe single exponential decay of the MA precursor upon irradiation and the quantum yield for MA photodissociation is measured to be Φ = 0.26(2) consistent with a weak pH2 cage effect. By comparing to gas-phase results, we show the in situ photolysis results in greater production of molecular products (CH2═NH + H2) compared to radical products (CH3NH + H) consistent with the idea of partial caging of the H atom photofragments. The information gained in this work can be used to guide future photolysis studies in pH2 matrixes.
Related Concept Videos
NMR Spectroscopy Of Amines
¹H NMR of Labile Protons: Deuterium (²H) Substitution
Mass Spectrometry of Amines
NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones
Proton (¹H) NMR: Chemical Shift
Absorption signals of all the protium nuclei...
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...


![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)