- Principles of absorption and emission spectroscopy (energy, reactivity and structure in singlet and triplet electronic excited states, Jablonski diagram).
- Timescales and mechanisms of fast and ultrafast processes (radiative decay, rotational motion, vibrational motion, internal conversion and intersystem crossing, vibrational relaxation, collisions in liquids).
- Potential energy surfaces of the ground state (S0) and excited state (S1 or T1) and of various processes following the initial excitation. Structure (geometry) changes in the excited state as an important path of deactivation in radiationless physical processes and photochemical reactions. Relation between physical processes and chemical reactions: rotation and isomerization reactions, vibration and dissociation reactions.
- Short-lived species formed in photochemical reactions: radicals, radical-ions, dimers, complexes. The effects of concentration of the substance studied, of the solvent properties and of the wavelength of the radiation absorbed. Energy transfer processes, sensitizers and quenchers.
- Storage and conversion of solar energy.
- Instruments and methods of investigation of photophysical processes and photochemical reactions. Steady-state and time-resolved (laser) absorption and emission spectroscopy.
- Application of sensitization and/or quenching processes in studies of mechanism and dynamics of photophysical and photochemical processes, using time-resolved and steady-state spectroscopy. Stern-Volmer equation
- Sunscreens – mechanism of action, composition, energy dissipation
- Labs include nano- and femotosecond transient absorption spectroscopy, laser spectroscopy.
The course aims to understand the properties of molecules in electronically excited states as compared to the ground state; understand the effects of excited states on the exceptionally high reactivity and structural changes of the excited molecules. Get to know the most important types of photophysical processes and photochemical reactions. Familiarize the students with spectroscopic methods used in photochemical and photophysical studies, including the steady-state and time-resolved absorption and emission spectroscopy and their application in research and analytical workflow in chemistry, physics, biology and medicine, in both routine and novel studies.
- H. Zewail: Ultrafast Molecular Reaction Dynamics in Real-Time, Ann. Rev. Phys. Chem. 41, 15, 1990
- G. R. Fleming: Chemical Applications of Ultrafast Spectroscopy, Oxford Univ. Press, 1986
- M. A. El-Sayed, I. Tanaka, Y. Molin: Ultrafast Processes in Chemistry and Photobiology, Blackwell Science 1995
- F. C. De Schryver, S. De Feyter, G. Schweitzer: Femtochemistry, Wiley-VCH, 2001