AUTHOR=Pei Linsen , Farrar James M. 

TITLE=A Velocity Map Imaging Study of the Reactions of O+ (4S) With CH4

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00227

DOI=10.3389/fchem.2019.00227

ISSN=2296-2646

ABSTRACT=<p>We present a velocity map imaging study of the key ion-molecule reactions occurring in the O<sup>+</sup>(<sup>4</sup>S<sub>3/2</sub>) + CH<sub>4</sub> (<bold>X</bold><sup>1</sup>A<sub>1</sub>) system at collision energies of 1.84 and 2.14 eV. In addition to charge transfer to form CH<inline-formula><mml:math id="M1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:math></inline-formula> (<bold>X</bold><sup>2</sup>B<sub>2</sub>), we also present data on formation of CH<inline-formula><mml:math id="M2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mrow></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:math></inline-formula> (<bold>X</bold><sup>1</sup>A<sub>1</sub>'), for which the experimentally determined images provide clear confirmation that the products arise from dissociative charge transfer rather than hydride transfer. Experimental data are also presented on the formation of HCO<sup>+</sup> through a transient [OCH<sub>4</sub>]<sup>+</sup> complex living many rotational periods. Plausible reaction pathways and intermediate structures are presented to give insight into the routes for formation of these reaction products.</p>