On the photoabsorption by permanganate ions in vacuo and the role of a single water molecule. New experimental benchmarks for electronic structure theory.

Autor: Houmøller J; Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark., Kaufman SH, Støchkel K, Tribedi LC, Brøndsted Nielsen S, Weber JM
Jazyk: angličtina
Zdroj: Chemphyschem : a European journal of chemical physics and physical chemistry [Chemphyschem] 2013 Apr 15; Vol. 14 (6), pp. 1133-7. Date of Electronic Publication: 2013 Feb 01.
DOI: 10.1002/cphc.201300019
Abstrakt: We report electronic spectra of mass-selected MnO4(-) and MnO4(-)⋅H2O using electronic photodissociation spectroscopy. Bare MnO4(-) fragments by formation of MnO3(-) and MnO2(-), while the hydrated complex predominantly decays by loss of the water molecule. The band in the visible spectral region shows a well-resolved vibrational progression consistent with the excitation of a Mn-O stretching mode. The presence of a single water molecule does not significantly perturb the spectrum of MnO4(-). Comparison with the UV/Vis absorption spectrum of permanganate in aqueous solution shows that complete hydration causes a small blueshift, while theoretical models including a dielectric medium have predicted a redshift. The experimental data can be used as benchmarks for electronic structure theory methods, which usually predict electronic spectra in the absence of a chemical environment.
(Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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