Forschungsgebiete

• Zeitaufgelöste Dynamik und Spektroskopie chemischer Elementarschritte untersucht mit kurzen Laserpulsen
• Rotationskohärenz-Spektroskopie [Kooperation mit der Univ. Frankfurt/M.]
• Femtosekunden zeitaufgelöster Protonentransfer in Azaaromat/Solvat-Komplexen [Kooperation mit der Univ. Frankfurt/M.]
• Femtosekunden-Spektroskopie mehrkerniger Metall-Ligand-Systeme in der Gasphase

Mitarbeit in wissenschaftlichen Netzwerken:

EU-Projekt: Wissenschaftliche Kooperation mit osteuropäischen Ländern

INTAS Research Project (03-50-5765), 2004-2007

Titel: Spectroscopy and laser control of ultrafast molecular-scale dynamics of photodissociation and photochemical reactions.

Publikationen

41) Separation of different hydrogen-bonded clusters by femtosecond UV-ionization detected Infrared spectroscopy: 1H-pyrrolo[3,2-h]quinoline(H₂O)_n=1,2 complexes Y. Nosenko, M. Kunitski, C. Riehn, R. P. Thummel, A. Kyrychenko, J. Herbich, J. Waluk, B. Brutschy, J. Phys. Chem. 112 (2008) 1150-1156.

40) Pseudorotation of pyrrolidine and short-lived excited state of 7-(2’-pyridyl)-indole studied by femtosecond spectroscopy in the gas phase, M. Kunitski, Y. Nosenko, V. V. Matylitsky, C. Riehn, B. Brutschy, Femtochemistry and Femtobiology 8, 2007, Conference Proceedings.

39) Detection and structural characterization of clusters with ultrashort-lived electronically excited states: IR absorption detected by femtosecond multi-photon ionization, Y. Nosenko, M. Kunitski, R. P. Thummel, A. Kyrychenko, J. Herbich, J. Waluk, C. Riehn, B. Brutschy, J. Am. Chem. Soc. 128 (2006) 10000-10001.

38) Missing levels lead to additional lines: effect of nuclear spin statistics on femtosecond degenerate four-wave mixing of polyatomic systems , C. Riehn, V. V. Matylitsky, M. I. Kunitski, M. F. Gelin, B. Brutschy, Phys. Chem. Chem. Phys. 7 (2005) 3955-3962.

37) Double Hydrogen Bonding of Acetic Acid studied by Femtosecond Degenerate Four-wave Mixing, C. Riehn, V. V. Matylitsky, M. F. Gelin, B. Brutschy, Mol. Phys. 103 (2005), 1615-1623.

36) New Schemes and Recent Results for High-Resolution Rotational Coherence Spectroscopy with Picosecond and Femtosecond Laser Pulses, C. Riehn, V. V. Matylitsky, A. Weichert, M. F. Gelin, W. Jarzeba, B. Brutschy, Femtochemistry and Femtobiology, M. M. Martin and J. T. Hynes (Eds.), Elsevier, Amsterdam (2004), p.73-76.

35) The Structure of Carboxylic Acid Dimers: Results by Femtosecond Degenerate Four-Wave Mixing Spectroscopy, V. V. Matylitsky, C. Riehn, M. F. Gelin, B. Brutschy, Femtochemistry and Femtobiology, M. M. Martin and J. T. Hynes (Eds.), Elsevier, Amsterdam (2004), p.65-68.

34)Insights into the Structure of Cyclohexane from Femtosecond Degenerate Four-wave Mixing Spectroscopy and Ab Initio Calculations, C. Riehn, V. V. Matylitsky, W. Jarzeba, B. Brutschy, P. Tarakeshwar, K. S. Kim, J. Am. Chem. Soc. 125 (2003) 16455-16462.

33)The formic acid dimer (HCOOH)₂ probed by time-resolved structure selective spectroscopy, V. V. Matylitsky, C. Riehn, M. F. Gelin, B. Brutschy, J. Chem. Phys. 119 (2003), 10553-10562.

32)The time domain fingerprints of a“perpendicular” rotational Raman band: formic acid studied by femtosecond degenerate four-wave mixing, C. Riehn, V. V. Matylitsky, M. F. Gelin, J. Raman. Spectrosc. 34 (2003) 1045-1050.

31)Rotational recurrences in thermal ensembles of nonrigid molecules, M. F. Gelin, C. Riehn, V. V. Matylitsky, B. Brutschy, Chem. Phys. 290 (2003) 307-318.

30) ROTATIONAL COHERENCE SPECTROSCOPY OF JET-COOLED MOLECULES BY FEMTOSECOND DEGENERATE FOUR-WAVE MIXING: NON-RIGID SYMMETRIC AND ASYMMETRIC TOPS, W. JARZEBA, V. V. MATYLITSKY, C. RIEHN, B. BRUTSCHY, CHEM. PHYS. LETT., 368 (2003) 680-689.

29)Femtosecond degenerate four-wave mixing study of benzene in the gas phase, V. V. Matylitsky, W. Jarzeba, C. Riehn, B. Brutschy, J. Raman Spectrosc. 33 (2002) 877-883.

28)Structure and binding energy of the phenol dimer: Correlated ab initio calculations compared with results from rotational coherence spectroscopy, P. Hobza, C. Riehn, A. Weichert, B. Brutschy, Chem. Phys. 283 (2002) 331-339.

27)High-resolution pump-probe rotational coherence spectroscopy - rotational constants and structure of ground and electronically excited states of large molecules and clusters, C. Riehn (Feature-Artikel), Chem. Phys. 283 (2002) 297-329.

26)Rotational coherence spectroscopy of benzene by femtosecond degenerate four-wave mixing, W. Jarzeba, V. V. Matylitsky, A. Weichert, C. Riehn, Phys. Chem. Chem. Phys. 4 (2002) 451-454.

25)Time-resolved rotational spectroscopy of para-difluorobenzene-Ar, A. Weichert, C. Riehn, V. V. Matylitsky, W. Jarzeba, B. Brutschy, J. Mol. Struct. 612 (2002) 325-337.

24)On the microscopic interaction of p-chlorofluorobenzene with water, C. Riehn, B. Reimann, K. Buchhold, H.-D. Barth, S. Vaupel, B. Brutschy, P. Tarakeshwar, K. S. Kim, J. Chem. Phys. 115 (2001) 10045-10047.

23) Implementation of a High-Resolution Two-Color Spectrometer for Rotational Coherence Spectroscopy in the Picosecond Time Domain, A. Weichert, C. Riehn, H.-D. Barth, G. Lembach, M. Zimmermann, B. Brutschy, D. Podenas, Rev. Sci. Instrum. 72 (2001) 2697-2708.

22)Probing benzene in a new way: high-resolution time-resolved rotational spectroscopy, C. Riehn, A. Weichert, und B. Brutschy, J. Phys. Chem. A 105 (2001) 5618-5621.

21)High-resolution Rotational Coherence Spectroscopy of the Phenol Dimer, A. Weichert, C. Riehn, und B. Brutschy, J. Phys. Chem. A 105 (2001) 5679-5691.

20)State-selective Rotational Coherence Spectroscopy by Two-Color Pump-Probe Schemes, A. Weichert, C. Riehn, and B. Brutschy in The Twelfth International Conference on Ultrafast Phenomena, OSA Technical Digest (Optical Society of America, Washington DC, 2000), pp. 385-387.

19) Rotational coherence spectroscopy of para-cyclohexylaniline by stimulated Raman-induced fluorescence depletion and stimulated emission pumping, A. Weichert, C. Riehn, und B. Brutschy, J. Chem. Phys. 113 (2000) 7830.

18) The molecular structure of para-cyclohexylaniline. Comparison of results obtained by X-ray diffraction with gas phase laser experiments and ab initio calculations, C. Riehn, A. Degen, A. Weichert, M. Bolte, E. Egert, B. Brutschy, P. Tarakeshwar, und K. S. Kim, J. Phys. Chem. A 104 (2000) 11593-11600.

17) Mass-selective rotational coherence spectroscopy by (1+1’) pump-probe photoionization, C. Riehn, A. Weichert, and B. Brutschy, Phys. Chem. Chem. Phys. 2 (2000) 1873.

16) High-Resolution Rotational Coherence Spectroscopy of para-Cyclohexylaniline, C. Riehn, A. Weichert, U. Lommatzsch, M. Zimmermann, und B. Brutschy, J. Chem. Phys. 112 (2000) 3650.

15) Van der Waals Isomers and Ionic Reactivity of the Cluster System para-Chlorofluorobenzene/Methanol, C. Riehn, K. Buchhold, B. Reimann, S. Djafari, H.-D Barth, B. Brutschy, P. Tarakeshwar, and K. S. Kim, J. Chem. Phys. 112 (2000) 1170.

14) Beitrag zur Femtochemistry IV, 18.-22.7.1999, Leuven, Belgien: Picosecond-resolved rotational coherence spectroscopy of large molecules and clusters - ground and excited state rotational constants, C. Riehn, A. Weichert, M. Zimmermann, und B. Brutschy.

13) Rotational Coherence Spectroscopy of para-difluorobenzene-Ar, C. Riehn, A. Weichert, M. Zimmermann, und B. Brutschy, Chem. Phys. Lett. 299 (1999) 103

12) An experimental study of HF photodissociation: Spin-orbit branching ratio and infrared alignment, J. Zhang, C. Riehn, M. Dulligan, C. Wittig, J. Chem. Phys. 104 (1996) 7027

11) Unimolecular decomposition of NO₃: The NO + O₂ threshold regime, K. Mikhaylichenko, C. Riehn, L. Valachovic, A. Sanov, C. Wittig, J. Chem. Phys. 105 (1996) 6807

10) Vibronic Interactions in NO₃ - from the ²E' Origin Region to the NO + O₂ Reactive Channel, L. Valachovic, C. Riehn, K. Mikhaylichenko, C. Wittig, Chem. Phys. Lett. 258 (1996) 644

9) Photoinitiated Reactions of Several Nitrogen Oxides: Timescales and Mechanisms, P. I. Ionov, S. I. Ionov, I. Bezel, C. Riehn, K. Mikhaylichenko, L. Valachovic, C. Wittig, in: Femtochemistry, M. Chergui (Ed.), World Scientific, London, 1995

8) Propensities toward C₂H(A ²) in acetylene photodissociation, J. Zhang, C. Riehn, M. Dulligan, C. Wittig, J. Chem. Phys. 103 (1995) 6815

7) IR Depletion Spectroscopy - a Method for characterizing a Microsolvation Environment, C. Riehn, C. Lahmann, B. Wassermann, B. Brutschy, Chem. Phys. Lett. 197 (1992) 443

6) Proton Transfer in Mixed Molecular Aggregates After Resonant Two-Photon Ionization, C. Riehn, C. Lahmann, B. Brutschy, H. Baumgärtel, Ber. Bunsenges. Phys. Chem. 96 (1992) 1164

5) The Structure of Mixed Reactive Aggregates studied by the Combination of IR Depletion and Resonant Two-Photon Ionization (R2PI) Spectroscopy, C. Riehn, B. Wassermann, C. Lahmann, B. Brutschy, Ber. Bunsenges. Phys. Chem. 96 (1992) 1161.

4) On the Role of Charge Transfer in Nucleophilic Substitution Reactions in Clusters of 1-Fluoro-n-chlorobenzene cations with Ammonia, C. Riehn, C. Lahmann, B. Brutschy, J. Phys. Chem. 96 (1992) 3626.

3)Structural aspects of chemical reactions in molecular clusters studied with resonant two photon ionization, C. Riehn, J. Awdiew, J. Eggert, B. Wassermann, B. Brutschy and H. Baumgärtel, J. Mol. Struct. 249 (1991) 33.

2)Investigation of reaction barriers in mixed organic aggegates by two-color resonant two photon ionization, J. Awdiew, C. Riehn, B. Brutschy and H. Baumgärtel, Ber. Bunsenges. Phys. Chem. 94 (1990) 1353.

1)C-C and C-H Bond Splits of Laser-Excited Aromatic Molecules. 3. UV Multiphoton Excitation Studies, H. Hippler, C. Riehn, J. Troe and K.-M. Weitzel, J. Phys. Chem. 94 (1990) 6321.

Sonstige Schriften

F)Buchbesprechung: Molecular Physics,W. Demtröder, C. Riehn, Nachrichten aus der Chemie, GdCh (Juli/August 2006).

E)Trendbericht Physikalische Chemie: Spektroskopische Strukturaufklärung in der Gasphase, C. Riehn, Nachrichten aus der Chemie, GdCh (März 2006).

D)Molekulare Gymnastik: Rotationen, Schwingungen und Chemische Reaktionen – Struktur und Dynamik beobachtet mit kurzen Laserpulsen, J. Wachtveitl, C. Riehn, Forschung Frankfurt, 3-4 (2003) 27-31.

C) Hochaufgelöste Rotationskohärenz-Spektroskopie mit kurzen Laserpulsen – die Struktur großer Moleküle und molekularer Aggregate im Grundzustand und elektronisch angeregten Zustand, Christoph Riehn, Habilitationsschrift, Johann Wolfgang Goethe-Universität Frankfurt/M., (November 2002).

B) Laserspektroskopische Untersuchungen zur Reaktivität und Struktur molekularer Aggregate, Christoph Riehn, Dissertation, Freie Universität Berlin, 165 S. (1992).

A)Zur UV-Multiphotonenanregung großer Moleküle, Christoph Riehn, Diplomarbeit, Institut für Physikalische Chemie, Georg-August-Universität Göttingen, 118 S.(1988).