Anomalous behavior observed upon annealing and photodetachment of anionic copper carbonyl clusters in argon matrices Ryan M. Ludwig, Michael E. Goodrich, David T. Moore Chemistry Department, Lehigh University 69 th ISMS, Univ. Illinois Urbana-Champaign June 17, 2014
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Anomalous behavior observed upon annealing and photodetachment of anionic copper carbonyl clusters in argon matrices Ryan M. Ludwig, Michael E. Goodrich,
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Anomalous behavior observed upon annealing and photodetachment of anionic copper carbonyl clusters in argon matrices
Ryan M. Ludwig, Michael E. Goodrich, David T. Moore
• annealing neutrals eliminates new spectral features
20K
visibleirrad.
25K
30K
1750 1800 1850 1900 1950 2000 20500.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
D
B
C
Abs
orba
nce
(x10
-2 O
.D.)
Wavenumber (cm-1)
A20K
visibleirrad.
25K
30Kdetach
e-
detach
e-
anneal anneal
vertical photodetachment product (!!)
anions neutrals
“High-resolution” spectroscopy
High resolution (0.125 cm-1) FTIR fine structure
• > 20 resolved peaks in region of anionic tricarbonyl
• also less structure in neutral region when detach precedes anneal
• Assignment: reproducible, (meta)stable matrix “sites” long-range pertubations from cations?
1800 1850
0.000
0.005
0.010
Ab
sorb
an
ce
Wavenumber (cm-1)
30 K anneal
vis.
1900 2000 2050
0.00
0.02
Abs
orba
nce
Wavenumber (cm-1)
1890 1980 1995 20100.0
0.2
0.4
0.6
0.8
1.0
Abs
orba
nce
(x10
-2 O
.D.)
Wavenumber (cm-1)
Conclusions
• Neutralization observed during “dark” deposition at 20 K cation-anion electron transfer neutralization (?)
• anneal detach anneal cycle gives stepwise production of new anionic & neutral species kinetic trapping of vertical detachment product (?)
• high-resolution (0.125 cm-1) spectra reveals rich fine structure of instrument-limited lines perturbation of vibrational/electronic levels by electric field of adjacent cations?
• GOOD THEORY IS DESPERATELY NEEDED!!!
Acknowledgements
Moore Group
Angela Smith Nina Finamore Ryan Ludwig Mike Goodrich Becky Klimas (M.S.) Alex Hunter (M.S.)
undergraduates
Edric Miro Gavin Erin Hassell Tony Thompson Christina Marrone Chris Caputo Nick Greybush Ankit Pokherel Nick Voellinger