Work Group Prof. Dr. F. Temps

Vibrational & Rotational Spectroscopy for Molecular Dynamics

Spectroscopy not only provides basic insight into the structures of molecules and molecular aggregates, it also reveals details on their dynamics that cannot easily be extracted by other methods. Following Christopher Columbus, who learned that there are two ways to India, by turning East or by turning West, the analysis of molecular spectra provides an equally important alternative route to obtaining molecular dynamics information compared to time-resolved measurements. 

   

Molecular aggregates

The spectroscopy of the indazole molecule is of considerable interest for the tendency of the molecule to form hydrogen-bonded dimers and larger clusters. In the dimer, the excited electronic states exhibit weak exciton splittings which mimic similar interactions in nucleobase pairs.

Important papers:

  • H. Nicken, F. Temps, E. Jalviste, "Dispersed Fluorescence Spectra of 1H- and 1D-Indazole", Z. Phys. Chem. 225, 1457 - 1469 (2011). DOI: 10.1524/zpch.2011.0197.
  • E. Jalviste, S. Dziarzhytski, F. Temps, "Electronic Spectra of Hydrogen-Bonded Self and Water Complexes of Indazole", Z. Phys. Chem. 222, 695 - 714 (2008).  DOI: 10.1524/zpch.2008.5347

    

FTMW spectroscopy

Fourier transform microwave spectroscopy (FTMW) spectroscopy in combination with either flash pyrolysis or excimer laser photolysis of suitable precursours allows us to be record high resolution rotational spectra of a series chemically important free radicals.  

  

MB-FTMW Spectrometer.jpg
 
Molecular Beam - Fourier-Transform Microwave Spectrometer.             (c) CAU Kiel

     

Important papers:

  • T. Pancur, K. Brendel, N. Hansen, H. Mäder, V. Markov, F. Temps, "Microwave Spectra of the 35Cl and 37Cl Isotomopers of Dichloromethylene: Nuclear Quadrupole, Spin-Rotation and Nuclear Shielding Constants from the Hyperfine Structures of Rotational Lines," J. Mol. Spectrosc. 232, 375 - 379 (2005).
  • N. Hansen, H. Mäder, F. Temps, "Rotational Transitions of the C2H3O Radical Detected by Pulsed Laser Photolysis - Molecular Beam - Fourier Transform Microwave Spectroscopy", J. Mol. Spectrosc. 209, 278 - 279 (2001).
  • N. Hansen, H. Mäder, F. Temps, "The Rotational Spectrum of CCl2 (X 1A1) Observed by Molecular Beam - Fourier Transform Microwave Spectroscopy", Phys. Chem. Chem. Phys. 3, 50 - 55 (2001).
  • N. Hansen, H. Mäder, F. Temps,  "Nuclear Spin-Rotation Interaction in CF2 (X 1A1) Observed by Fourier-Transform Microwave Spectroscopy", Chem. Phys. Lett. 327, 97 - 103 (2000).

   

Combustion diagnostics

Laser spectroscopy provides a versatile toolbox for the diagnostics of the environment, including the atmosphere and combustion processes, or for bio-medical diagnostics. Among other applications, we have a focus on chemiluminescence (CL) spectroscopy, laser induced fluorescemce (LIF) and particle imaging velocimetry (PIV) to look into fine details in flames and in a one-cylinder internal combustion test engine.

Important papers:

  • A. Thrun, F. Temps, J. Bauer, "Investigation of Turbulent Combustion and Flame Extinction in a One-Cylinder Internal Combustion Engine", VDI-Nachrichten 2267, 723 - 728 (2015).

  

Collisional intersystem crossing

Important paper:

  • U. Bley, F. Temps, "Collision-Induced Intersystem Crossing of CH2 from a 1A1 to X 3B1: A Case Study of the Mixed- State Model", J. Chem. Phys. 98, 1058 - 1072 (1993).