TITLE:
Gas Phase Activation of Methane Molecule with Lead Benzene Dication Complex Ion, [Pb(Benzene)2]2+
AUTHORS:
Joseph K. Koka
KEYWORDS:
Lead, Benzene, Binding Energy, Methane Activation, Dication Complex Ion, Density Functional Calculations, Potential Energy Curve
JOURNAL NAME:
Materials Sciences and Applications,
Vol.10 No.2,
January
29,
2019
ABSTRACT: Motivated
by the search for ways of a more efficient usage of the ubiquitous, and unexploited resources of
methane, recent progress in the gas-phase activation of methane by metal dication complex ion is discussed.
The gas phase theoretical and experimental analysis on [Pb(Benzene)2]2+ was
conducted. The [Pb(Benzene)2]2+ complex ions were
prepared using a combination of the pick-up technique and high energy electron
impact, and then held in a cold ion trap. Excitation with tuneable UV radiation
resulted in the formation of [Pb(Benzene)2(H2O)]2+,
[Pb(Benzene)2(H2O)2]2+,
[Pb(Benzene)]+, Pb+ and Benzene+ ions when the
experimental results were analysed. The two optimised geometries of
[Pb(Benzene)2]2+ namely the C2V eclipse and C2 staggered were observed. Methane activation of [Pb(Benzene)2]2+ complex ion yielded [Pb(Benzene)2(Me)]2+.
[Pb(Benzene)2(H2O)(Me)2]2+, [Pb(Benzene)2(H2O)(Me)]2+, [PbBenzene(Me)3]2+ and
[Pb(Benzene)(Me)]2+. The PEC calculated binding energy of methane to
lead benzene dication complex ion was approximately 25.45% higher than the
value recorded on DFT calculation. This difference was due to the charge
differences on the lead metal centre. While the actual calculated charge on the
Pb metal in the optimised geometry was 1.68 the charge of +2 on the Pb metal
was considered in the PEC calculation.