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Spectroscopy and photochemistry of copper nitrate clusters
Tobias F Pascher1, Milan Ončák, Christian van der Linde
1Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria. Milan.Oncak@uibk.ac.at Martin.Beyer@uibk.ac.at.
Physical Chemistry Chemical Physics : PCCP
|April 28, 2021
Summary
Copper nitrate cluster anions were studied using UV/vis/NIR spectroscopy. Their electronic structure and photochemistry reveal decomposition pathways involving ligand-to-metal charge transfer and N-O bond photolysis.
Area of Science:
- Inorganic Chemistry
- Photochemistry
- Spectroscopy
Background:
- Copper nitrate cluster anions (Cu(ii)n(NO3)2n+1-, n ≤ 4) are investigated in the gas phase.
- Understanding their electronic structure and photochemistry is crucial for materials science.
Purpose of the Study:
- To provide detailed insight into the electronic structure of copper nitrate cluster anions.
- To elucidate the photochemistry and decomposition pathways of these clusters.
Main Methods:
- Gas-phase ultraviolet/visible/near-infrared (UV/vis/NIR) spectroscopy.
- Analysis of spectral bands including 3d-3d transitions, Ligand-to-Metal Charge Transfer (LMCT), and n-π* transitions.
Main Results:
- Spectra show 3d-3d bands in the vis/NIR and UV bands attributed to LMCT and n-π* transitions.
- Clusters decompose via loss of neutral copper nitrate or photochemical loss of a neutral NO3 ligand after LMCT.
- N-O bond photolysis in nitrate ligands leads to loss of nitrogen dioxide or an oxygen atom, observed in the UV region.
Conclusions:
- Decomposition channels compete on the ground state potential energy surface for smaller clusters.
- Photochemical N-O bond cleavage in nitrate ligands is a significant decomposition pathway.
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