Spectroscopy and Photochemical Kinetics
Many phenomena of nature can be traced back to molecular processes which, in series of "chemical elementary reactions", compose complicated reaction networks. In order to understand the latter, the elementary reactions have to be isolated in the laboratory and understood in their detailed atomic dynamics. Modern experimental techniques (laser flash photolysis, thermal excitation in shock waves, spectroscopic detection) and theoretical methods (quantum chemistry, reaction dynamics, molecular statistics) allow one to quantitatively understand the fine details of the dynamics and kinetics of the elementary processes involved. On this basis, "large reaction systems" like molecular clouds in astronomy (called "nebulae"), the terrestrial atmosphere, combustion processes in flames etc. today can be described quantitatively. This is of large fundamental as well as practical importance. Our group in this field studies reactions of neutral molecules, molecular ions, and electrons. Large ranges of temperatures (from a few up to thousands of degrees), of pressures (from small fractions up to thousands of atmospheres), and reaction times (from picoseconds to minutes) are studied experimentally. Employing detailed theoretical studies, data bases are constructed in international collaborations which form the input to large scale modeling of the mentioned reaction systems.
Selected publications
Dashevskaya, E. I., I. Litvin, E. E. Nikitin and J. Troe: Electron capture by polarizable dipolar targets: Numerical and an approximated capture probabilities. Journal of Physical Chemistry A 115, 6825-6830 (2011).
Hincelin, U., V. Wakelam, F. Hersant, S. Guilloteau, J. C. Loison, P. Honvault and J. Troe: Oxygen depletion in dense molecular clouds: a clue to a low O2 abundance? Astronomy & Astrophysics 530, A61 (2011).
Troe, J.: The thermal dissociation/recombination reaction of hydrogen peroxide H2O2(+M) ↔ 2OH(+M). III. Analysis and representation of the temperature and pressure dependence over wide ranges. Combustion and Flame 158, 594-601 (2011).
Cobos, C. J., A. E. Croce, K. Luther and J. Troe: Shock wave study of the thermal decomposition of CF3 and CF2 radicals. Journal of Physical Chemistry A 114, 4755-4761 (2010).
Dashevskaya, E. I., I. Litvin, E. E. Nikitin and J. Troe: Locking of the intrinsic angular momentum in the capture of quadrupole diatoms by ions. Molecular Physics 108, 873-882 (2010)
Fernandes, R. X., K. Luther and J. Troe: Contribution of the radical-complex mechanism to the rate of the reaction CH3+O2(+M) ↔ CH3O2(+M) at high pressures. Journal of Physical Chemistry A 114, 9963-9968 (2010).
