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  - 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  - Löhmannsröben, Hans-Gerd
A1  - Ariese, F.
A1  - Bader, Arjen N.
A1  - Gooijer, C.
A1  - Miljanic, O. S.
A1  - Iwamoto, M.
A1  - Vollhardt, K. Peter C.
A1  - Puchta, R. ; van Eikema Hommes, N. J. R.
T1  - Deuteration effects on the vibronic structure of the fluorescence spectra and the internal conversion rates of triangular [4]Phenylene
N2  - Deuteration effects on the vibronic structure of the emission and excitation spectra of triangular [4]phenylene (D3h[4]phenylene) were studied using laser-excited Shpolskii spectroscopy (LESS) in an octane matrix at 4.2 K. For correct assignment of the vibrational modes, the experimental results were compared with calculated frequencies (B3LYP/6-31G*). CH vibrations were identified by their characteristic isotopic shifts in the spectra of deuterated triangular [4]phenylenes. Two CC stretching modes, at 100 cm–1 and 1176 cm–1, suitable as probes for bond strength changes in the excited state, were identified. The isotope effect on the internal conversion rates of triangular [4]phenylene was evaluated from measurements of temperature dependent lifetime. Isotope dependency and the magnitude of the internal conversion rates indicate that internal conversion in triangular [4]phenylene is most likely induced by CH vibrations. The results obtained by LESS and lifetime measurements were compared with PM3 PECI calculations of the excited state structure. The theoretical results and the relation between ground and excited state vibration energies of the 1176 cm–1 probe vibration indicate a reduction of bond alternation of the central cyclohexatriene ring in the excited state.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 002 
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-11881
ER  - 
TY  - JOUR
A1  - Dosche, Carsten
A1  - Kumke, Michael Uwe
A1  - Löhmannsröben, Hans-Gerd
A1  - Ariese, Freek
A1  - Bader, Arjen N.
A1  - Gooijer, Cees
A1  - Miljanic, Ognjen S.
A1  - Iwamoto, M.
A1  - Vollhardt, K. Peter C.
A1  - Puchta, Ralph
A1  - Hommes, N. J. R. V.
T1  - Deuteration effects on the vibronic structure of the fluorescence spectra and the internal conversion rates of triangular [4]phenylene
N2  - Deuteration effects on the vibronic structure of the emission and excitation spectra of triangular [ 4] phenylene (D-3h [4]phenylene) were studied using laser-excited Shpol'skii spectroscopy (LESS) in an octane matrix at 4.2 K. For correct assignment of the vibrational modes, the experimental results were compared with calculated frequencies (B3LYP/6-31G*). CH vibrations were identified by their characteristic isotopic shifts in the spectra of deuterated triangular [4]phenylenes. Two CC stretching modes, at 100 cm(-1) and 1176 cm(-1), suitable as probes for bond strength changes in the excited state, were identified. The isotope effect on the internal conversion rates of triangular [4] phenylene was evaluated from measurements of temperature dependent lifetime. Isotope dependency and the magnitude of the internal conversion rates indicate that internal conversion in triangular [4] phenylene is most likely induced by CH vibrations. The results obtained by LESS and lifetime measurements were compared with PM3 PECI calculations of the excited state structure. The theoretical results and the relation between ground and excited state vibration energies of the 1176 cm(-1) probe vibration indicate a reduction of bond alternation of the central cyclohexatriene ring in the excited state
Y1  - 2004
SN  - 1463-9076
ER  - 
TY  - JOUR
A1  - Kumke, Michael Uwe
A1  - Dosche, Carsten
A1  - Flehr, Roman
A1  - Trowitzsch-Kienast, Wolfram
A1  - Löhmannsröben, Hans-Gerd
T1  - Spectroscopic characterization of the artificial siderophore pyridinochelin
Y1  - 2006
UR  - http://www.znaturforsch.com/c.htm
SN  - 0939-5075
ER  - 
TY  - JOUR
A1  - Luschtinetz, Franziska
A1  - Dosche, Carsten
A1  - Kumke, Michael Uwe
T1  - Influence of streptavidin on the absorption and fluorescence properties of cyanine dyes
N2  - Cyanine dyes have become widely used fluorescence labels in clinical and biological chemistry. In particular, cyanine dyes with excitation wavelengths lambda(ex) > 600 nm are often used in biological applications. However, aggregation behavior and matrix effects on cyanine fluorescence are not fully understood yet and interfere with the data interpretation. In this study, we analyzed the spectroscopic characteristics of a model system consisting of the biotinylated cyanine dyes DY-635 and DY-647 and their streptavidin conjugates. On the basis of the spectroscopic data, the interaction processes between cyanine dye molecules and proteins are discussed. Binding to streptavidin had a significant influence on both fluorescence and anisotropy decays of the cyanine dyes investigated. In particular, the fluorescence anisotropy was significantly altered, making it a promising detection parameter for bioanalytical applications in connection with the cyanine dyes used in the present study. In order to evaluate the time-resolved anisotropy, the introduction of a sophisticated kinetic model was required to describe the contributions from different fluorescing species properly. The rotational motion of streptavidin-bound dyes was analyzed using the associated anisotropy model, which allowed discrimination between contributions from different microenvironments. The anisotropy decay times increased by a factor of up to 20 due to protein binding.
Y1  - 2009
UR  - http://pubs.acs.org/journal/bcches
U6  - https://doi.org/10.1021/Bc800497v
SN  - 1043-1802
ER  - 
TY  - JOUR
A1  - Techen, Anne
A1  - Hille, Carsten
A1  - Dosche, Carsten
A1  - Kumke, Michael Uwe
T1  - Fluorescence study of drug-carrier interactions in CTAB/PBS buffer model systems
JF  - Journal of colloid and interface science
N2  - The well-known cationic surfactant hexadecyltrimethylammonium bromide (CTAB) was used as a model carrier to study drug-carrier interactions with fluorescence probes (5-hexadecanoylaminofluorescein (HAF) and 2,10-bis-(3-aminopropyloxy)dibenzo[aj]perylene-8,16-dione (NIR 628) by applying ensemble as well as single molecule fluorescence techniques. The impact of the probes on the micelle parameters (critical micelle concentration, average aggregation number, hydrodynamic radius) was investigated under physiological conditions. In the presence of additional electrolytes, such as buffer, the critical micelle concentration decreased by a factor of about 10. In contrast, no influence of the probes on the critical micelle concentration and on average aggregation number was observed. The results show that HAF does not affect the characteristics of CTAB micelles. Analyzing fluorescence correlation spectroscopy data and time-resolved anisotropy decays in terms of the "two-step" in combination with the "wobbling-in-cone" model, it was proven that HAF and NIR 628 are differently associated with the micelles. Based on ensemble and single molecule fluorescence experiments, intra- and intermicellar energy transfer process between the two dyes were probed and characterized.
KW  - Hexadecyltrimethylammonium bromide
KW  - 5-Hexadecanoylaminofluorescein
KW  - 2,10-Bis-(3-aminopropyloxy)dibenzo[aj]perylene-8,16-dione
KW  - Fluorescence correlation spectroscopy
KW  - Fluorescence anisotropy
KW  - Single-molecule FRET
Y1  - 2012
U6  - https://doi.org/10.1016/j.jcis.2012.03.063
SN  - 0021-9797
VL  - 377
SP  - 251
EP  - 261
PB  - Elsevier
CY  - San Diego
ER  -