TY  - JOUR
A1  - Dosche, Carsten
A1  - Kumke, Michael Uwe
A1  - Ariese, Freek
A1  - Bader, Arjen N.
A1  - Gooijer, Cees
A1  - Dosa, P. I.
A1  - Han, S.
A1  - Miljanic, Ognjen S.
A1  - Vollhardt, K. Peter C.
A1  - Puchta, Ralph
A1  - Hommes, N. J. R. V.
T1  - Shpol'skii spectroscopy and vibrational analysis of [N]phenylenes
Y1  - 2003
ER  - 
TY  - GEN
A1  - Dosche, Carsten
A1  - Kumke, Michael Uwe
A1  - Ariese, F.
A1  - Bader, Arjen N.
A1  - Gooijer, C.
A1  - Dosa, P. I.
A1  - Han, S.
A1  - Miljanic, O. S.
A1  - Vollhardt, K. Peter C.
A1  - Puchta, R.
A1  - Eikema Hommes, N. J. R. van
T1  - Shpol’skii spectroscopy and vibrational analysis of [N]phenylenes
N2  - Vibrationally resolved fluorescence spectra of four angular [N]phenylenes were recorded with laser excited Shpol’skii spectroscopy (LESS) in an n-octane matrix at 10 K. In general, the same vibrational frequencies were observed in the fluorescence excitation and emission spectra, indicating that the geometries of ground and electronically excited state are very similar. Because of intensity borrowing from the S2 state, vibrations of two different symmetries were observed in the fluorescence excitation spectra of angular [3]phenylene and zig-zag[5]phenylene. This finding allowed the location of the S2 state for these compounds. DFT calculations(RB3LYP/6-31G*) of the ground state vibrational frequencies were made. The calculated vibrational modes were in reasonably good agreement with the experimental data. A new very low-frequency vibration of approximately 100 cm-1 was predicted and experimentally confirmed for all [N]phenylenes investigated. This vibration seems to be unique for [N]phenylenes and is attributed to an in-plane movement of the carbon backbone.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 024 
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13075
ER  - 
TY  - GEN
A1  - Billard, Isabelle
A1  - Ansoborlo, Eric
A1  - Apperson, Kathleen
A1  - Arpigny, Sylvie
A1  - Azenha, M. Emilia
A1  - Birch, David
A1  - Bros, Pascal
A1  - Burrows, Hugh D.
A1  - Choppin, Gregory
A1  - Kumke, Michael Uwe
T1  - Aqueous solutions of Uranium(VI) as studied by time-resolved emission spectroscopy : a Round-Robin Test
N2  - Results of an inter-laboratory round-robin study of the application of time-resolved emission spectroscopy (TRES) to the speciation of uranium(VI) in aqueous media are presented. The round-robin study involved 13 independent laboratories, using various instrumentation and data analysis methods. Samples were prepared based on appropriate speciation diagrams and, in general, were found to be chemically stable for at least six months. Four different types of aqueous uranyl solutions were studied: (1) acidic medium where UO22+aq is the single emitting species, (2) uranyl in the presence of fluoride ions, (3) uranyl in the presence of sulfate ions, and (4) uranyl in aqueous solutions at different pH, promoting the formation of hydrolyzed species. Results between the laboratories are compared in terms of the number of decay components, luminescence lifetimes, and spectral band positions. The successes and limitations of TRES in uranyl analysis and speciation in aqueous solutions are discussed.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 005 
KW  - uranium (VI)
KW  - intercomparison
KW  - speciation
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12318
ER  -