Anomalous Behavior Observed Upon Annealing And Photodetachment Of Anionic Copper Carbonyl Clusters In Argon Matrices

Moore, David T

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https://hdl.handle.net/2142/51194 Copy

Description

Title

Anomalous Behavior Observed Upon Annealing And Photodetachment Of Anionic Copper Carbonyl Clusters In Argon Matrices

Author(s)

Moore, David T

Contributor(s)

Ludwig, Ryan M

Issue Date

2014-06-18

Keyword(s)

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

Abstract

"Using matrix isolation FTIR, we have observed the formation of anionic copper carbonyl complexes [Cu(CO)$_{n}$]$^{-}$ (n=1-3) following co-deposition of Cu$^{-}$ and counter-cations (Ar$^{+}$ or Kr$^{+}$) into argon matrices doped with CO.\footnote{Ryan M. Ludwig and David T. Moore, J. Chem. Phys. 139, 244202 (2013).} When the deposition is carried out at 20 K, weak bands corresponding to the neutral copper carbonyl complexes Cu(CO)$_{n}$ (n=1-3) are also observed, and these grow in steadily as the matrix is annealed up to 30 K. This is in contrast to what is observed at 10 K (c.f. ISMS 2014 abstract \#P631), where no appreciable neutral bands are observed, and indicates that some neutralization occurs during the formation of the complexes in the 20 K matrix. In addition, sharp peaks not previously observed grow in around the anionic bands upon annealing to 30 K; this is somewhat odd, since annealing typically simplifies the spectra of matrix samples as kinetically trapped metastable species relax to more stable forms. In this case, higher-resolution (0.125 \wn) spectra reveal considerable new fine structure, with 5 and 20 peaks appearing in the regions of the mono- and tricarbonyl anions, respectively, each of which nominally has but a single IR-active CO-stretching mode. These new features are tentatively assigned (at least in part) to electric-field-induced splitting arising from long-range interactions with cationic species in the matrix. A second anomalous feature of these spectra is that, upon photodetachment, several new bands are observed in the region of the neutral copper carbonyl species. Upon annealing these bands then disappear, with concomitant growth of the expected neutral bands. This behavior raises the exciting possibility that these transient bands represent metastable ""vertical detachment products"", where the neutral species has been kinetically trapped by the matrix in the geometry of the anion. Evidence supporting this interpretation will be presented."

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/51194

DOI

https://doi.org/10.15278/isms.2014.WG08

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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