Molecular Electronics and Spectroscopy
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Our experimental research is devoted to the photophysics of new molecules and organised molecular systems exhibiting properties that are potentially important for molecular (opto)electronics. A broad scope of compounds is examined: relatively simple organic molecules (e.g. new fluorescent labels, fluorophores with extreme dipole moment change on excitation, etc.), multichromophoric molecular systems, and complex biomacromolecules, and new types of polymers. Syntheses of new compounds are being carried out in collaborating laboratories (M. Nepraš, University Pardubice, CR, mainly).
Experimental investigations utilise a broad range of optical spectroscopy: steady state absorption and fluorescence, nanosecond to femtosecond fluorescence lifetimes and anisotropy measurements, time-resolved non-linear techniques. Experiments are performed at home except for some ultrafast (fs) measurements that are jointly performed in collaborating laboratories abroad.
Kinetics of primary photophysical processes is spectroscopically followed in a real time. We apply various methods for re-convolution and multiparameter fitting of experimental data, as well as computer simulations of the relaxation processes in question. Quantum chemical calculations of relevant molecular structures are carried out in collaboration with other quantum chemists and physicists (Charles University, Prague).
Special attention is currently devoted to intra-molecular electronic excitation energy transfer, electron density redistribution, excitonic interactions, related molecular dynamics, and to the relationship of those processes with molecular micro-surrounding. Connection of such fast processes with non-linear optical and/or electrical molecular properties will be investigated.
Our group has close scientific contacts and collaborations with partner laboratories abroad, as in Himeji Institute of Technology in Japan, at University of Göttingen and Max-Planck Institute in Göttingen, Germany; and Brown University, USA.
Projects supported by grants
- Excitonic Interactions in Molecular Systems: Dynamics and
Mechanisms of Excitation Energy Transfer. GA CR No. 202/98/0566
- Molecular Science: Processes of Electron and Proton Transfer and
Energy Exchange in the Gaseous and Condensed Phase, B: Energy
Transfer and Excitonic Interactions. MŠMT ER, Kontakt ME296 (1998)
- Solvent Relaxation in Bio-membranes. GA CR No. 203/99/0845
- Laser Systems, CTU research plan No. MSM 210000022
List of Selected Publications and Conference Contributions
- Bradforth, S., Jimenez, R., Fidler, V., Fleming, G., Nagarajan,
S., Norris, J., van Mourik, F., van Grondelle, R.: Ultrafast Energy
Transfer in the Core Light Harvesting Complex of the Photosynthetic
Bacterium Rhodobacter Sphaeroides Observed by Fluorescence
Upconversion. In: Ultrafast Phenomena IX., Springer-Verlag, 1994, p.
441.
- Vajda, S., Jimenez, R., Castner, Jr., E.W., Rosenthal, S.J.,
Fidler, V., Fleming, G.R.: Femtosecond through Nanosecond Time Scale
Solvation Dynamics in Pure Water and Inside the *-Cyclodextrin
Cavity. J.Chem.Soc. Faraday Trans. 91 1994, pp. 867-873
- Zhang, S.-L., Lang, M. J., Goodman, S., Durnell, C., Fidler, V.,
Fleming, G. R., Yang, N. C.,: Donor-Acceptor Interaction and
Photochemistry of Polymethylene-Linked Bichromophores in Solution,
J. Am. Chem. Soc. 118 (1996), pp. 9042-9051
- Hof, M., Vajda, Š., Fidler, V., Karpenko, V.,: Picosecond
Tryptophan Fluorescence of Human Blood Serum Orosomucoid. Collect.
Czech. Chem. Commun., 61 (1996), pp. 808-818
- Hof, M., Fleming, G.R., Fidler, V.: Time-Resolved Fluorescence
Study of a Calcium Induced Conformational Change in Prothrombin
Fragment I. Proteins: Structure, Function and Genetics, 24, 1996,
pp. 485-494
- Hutterer, R., Schneider, F.W., Fidler, V., Grell, E., Hof, M.:
Time-evolved Emission Spectra of Prodan and Patman in Large
Unilamellar Vesicle. J. Fluor., 7(1), 1997, pp. 161-163.
- Nepraš, M., Machalický, O., Šeps, M., Hrdina, R., Kapusta, P.,
Fidler, V.: Structure and Properties of Fluorescent Reactive Dyes:
Photophysics of Some Benzanthrone Derivatives. Dyes and Pigments 35,
1997, pp. 31-44
- Fidler, V., Kapusta, P., Nepraš, M., Schroeder, J., Rubtsov,
I.V., Yoshihara, K.: Ultrafast Electronic Energy Flow in a
Bichromophoric Molecule. Collect. Czech Chem. Commun. 63, 1998, pp.
1460-1472.
- Kapusta, P., Fidler, V., Nepraš, M., Blachut, T., Šeps, M.:
1-(Dichloro-1,3,5-Tria-zinyl)-Pyrene - A New Polarity Probe. in: Jan
Slavik, ed., Fluorescence Microscopy and Fluorescence Probes Vol. 2,
Plenum Press, New York 1998, pp. 133-139.
- Kapusta, P., Fidler, V., Nepraš, M., Šoustek, P., and Hof, M.;:
Reactive fluorescent N-trazinyl-1-aminopyrene derivatives, in:
Kotyk, A., Ed.: Fluorescence Microscopy and Fluorescent Probes 3,
Espero Publishing, Czech Republic, (1999) pp. 145-151
- Nepraš, M., Urbanec, J., Kapusta P., and Fidler, V.: Dvojí
fluorescence u některých derivátů 3-aminobenzanthronu, Chem. Listy,
94 (2000) 795-796
- Fidler, V., Kapusta, P., Nepraš, M., Schroeder, J., Rubtsov, I., V., and Yoshihara, K.: Femtosecond Fluorescence Anisotropy Kinetics as a Signature of Ultrafast Electronic Energy Transfer in Bichromophoric Molecules, Accepted to Zeitschrift für Physikalische Chemie, to be published in Apr./May (2001)