(395a) Direct Methylation of Cobaloxime By Low Temperature Methane Plasma in a Multiphase DBD µ-Plasmatron

Plasma-assisted heterogeneous catalysis and its potential in synthetic chemistry is being studied for the highly active species generated at mild conditions and high energy efficiency compared to traditional synthetic methods, as well as being environmentally green owing to the elimination of toxic solvents during synthesis processes. ^1–5 Micro dielectric-barrier-discharge (DBD) plasma reactors are suitable devices for the study of plasma synthetic chemistry since they offer homogeneous non-thermal plasma along with reduced transport limitations between plasma and liquid phase. ^6,7 Cobaloximes are receiving increasing attention for their roles in photoredox/organometallic cooperative catalysis.^8,9

A cobaloxime molecule is chosen as an example organometallic molecule for our study. Experiments were conducted in a multiphase µ-plasmatron, in which the multiphase mixing was previously evaluated. ¹⁰ Generation of methyl radicals was confirmed by in-situ optical emission in addition to circuit current measurement, which facilitated the study of plasma catalytic reactions. Directly methylation of a cobalt compound by methyl radicals was confirmed by its characteristic Raman shifts, which is exciting for it explored the potential of using methane as a feedstock in organometallic synthesis. The short reaction residence time also demonstrated “flash chemistry” made possible in a multiphase µ-plasmatron. The above work will be presented and discussed.

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