Single atom catalytic cyclotrimerization of v(acetylene)3+ studied with infrared spectroscopy

Marks, Joshua H

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https://hdl.handle.net/2142/100478 Copy

Description

Title

Single atom catalytic cyclotrimerization of v(acetylene)3+ studied with infrared spectroscopy

Author(s)

Marks, Joshua H

Contributor(s)

• Duncan, Michael A.
• Ward, Timothy B.

Issue Date

2018-06-22

Keyword(s)

Ions

Abstract

Vanadium cation is studied as a model system for single atom catalysis in the gas phase with infrared photodissociation spectroscopy. Intermediates in the cyclotrimerization of acetylene to form benzene are observed. V(C2H2)n + clusters are produced via laser vaporization of vanadium in a supersonic expansion of argon containing acetylene. Clusters of V(C2H2) +, V(C2H2)2 +, and V(C2H2)3 + are studied with infrared photodissociation spectroscopy with the aid of argon tagging in the C–H stretching region. These spectra are assigned on the basis of B3LYP computations. V(C2H2) + is a three membered metallacycle, where the hydrogens bend away from the vanadium. V(C2H2)2 + is a bimetallacycle where both acetylene ligands interact with vanadium symmetrically through their π-bonds in a C2v configuration. The structure of V(C2H2)3 + is found to vary with the concentration of acetylene in the supersonic expansion. At low concentrations of acetylene two isomers of V(C2H2)3 + are observed, a trimetallacycle, and a bimetallacycle which includes a five membered ring and a three membered ring. As the concentration of acetylene is increased past 5% the trimetallacycle decreases in abundance. Benzene is observed at yet higher concentration of acetylene. An expansion gas consisting of 15% acetylene in argon results in the exclusive formation of V(Bz)+.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100478

DOI

10.15278/isms.2018.FE07

Copyright and License Information

Copyright 2018 Joshua H. Marks

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