Skip to content

Observation of Rainbows in the Rotationally Inelastic Scattering of NO with CH4

Research output: Contribution to journalArticle

Original languageEnglish
Pages (from-to)7758-7767
Number of pages10
JournalJournal of Physical Chemistry A
Issue number36
Early online date23 Aug 2019
DateAccepted/In press - 21 Aug 2019
DateE-pub ahead of print - 23 Aug 2019
DatePublished (current) - 12 Sep 2019


Using a combination of velocity-map imaging and resonance-enhanced multiphoton ionization detection with crossed molecular beam scattering, the dynamics of rotational energy transfer have been examined for NO in collisions with CH4 at a mean collision energy of 700 cm-1. The images of NO scattered into individual rotational (jNO') and spin-orbit (Ω) levels typically exhibit a single broad maximum that gradually shifts from the forward to the backward scattering direction with increasing rotational excitation (i.e., larger ΔjNO). The rotational rainbow angles calculated with a two-dimensional hard ellipse model show reasonable agreement with the observed angles corresponding to the maxima in the differential cross sections extracted from the images for higher ΔjNO transitions, but there are clear discrepancies for lower ΔjNO (in particular, final rotational levels with jNO' = 7.5 and 8.5). The sharply forward scattered angular distributions for these lower ΔjNO transitions better agree with the predictions of an L-type rainbow model. The more highly rotationally excited NO appears to coincide with low rotational excitation of the co-product CH4, indicating a degree of rotational product-pair anticorrelation in this bimolecular scattering.



  • Full-text PDF (author accepted manuscript)

    Rights statement: This is the author accepted manuscript (AAM). The final published version (version of record) is available online via American Chemical Society at . Please refer to any applicable terms of use of the publisher.

    Accepted author manuscript, 1.81 MB, PDF document

    Embargo ends: 23/08/20

    Request copy


View research connections

Related faculties, schools or groups