Vibrational Spectroscopy And Theory Of Cu+(ch4)n And Ag+(ch4)n (n = 1 - 6)

Ashraf, Muhammad Affawn

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https://hdl.handle.net/2142/51011 Copy

Description

Title

Vibrational Spectroscopy And Theory Of Cu+(ch4)n And Ag+(ch4)n (n = 1 - 6)

Author(s)

Ashraf, Muhammad Affawn

Contributor(s)

• Metz, Ricardo B.
• Kocak, Abdulkadir

Issue Date

2014-06-19

Keyword(s)

Mini-symposium: Beyond the Mass-to-Charge Ratio: Spectroscopic Probes of the Structures of Ions

Abstract

Vibrational spectra are measured for Cu$^{+}$(CH$_{4}$)$_{n}$ and Ag$^{+}$(CH$_{4}$)$_{n}$ (n = 1 - 6) in the C-H stretching region (2500-3100 \wn) using photofragment spectroscopy. Spectra are obtained by monitoring CH$_{4}$ fragment loss following absorption of one photon (for n = 3 - 6), sequential absorption of multiple photons for Ag$^{+}$(CH$_{4}$)$_{n}$(n = 1 - 2) or one photon absorption by Ar-tagged Cu$^{+}$(CH$_{4}$)$_{n}$ (for n = 1-2). Determination of the structures of the complexes was done by comparing calculated vibrational spectra of low-lying candidate structures to the observed IR photodissociation spectra. Calculations were carried out using both the B3LYP and CAM-B3LYP hybrid density functionals with the 6-311++G(3df,3pd) basis set for Cu, C and H and the aug-cc-pVTZ basis with an effective core potential (ECP) for Ag. Calculations predict that the positions and intensities of bands in the C-H stretching region depend strongly on the coordination of the CH$_{4}$ to the metal ($\eta$$^{2}$ or $\eta$$^{3}$) and on the M-C bond length, and thus is sensitive to the number of ligands in the first and second shell. For clusters with $n\le{4}$ these ions adopt symmetrical structures with $\eta$$^{2}$ methane coordination. For copper, the larger clusters are primarily formed by addition of second-shell CH$_{4}$ to a tetrahedral core; silver primarily coordinates the 5th and 6th ligands in the first shell.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/51011

DOI

https://doi.org/10.15278/isms.2014.RG11

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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