Core course in MSc Chemistry – Energy & Sustainability, elective course MSc Chemistry, MSc Life Science and Technology
BSc in MST with a major in Chemistry or BSc LST with a minor advanced LST, are better prepared for the PC course. Other students should have a basic knowledge in basic quantum chemistry (atomic s, p, d orbitals, molecular orbitals, meaning of the wave function), organic chemistry (covalent bond, pi systems and conjugation), inorganic chemistry (crystal field theory), chemical kinetics (1st and 2nd order rate laws, elementary processes, transition states), and biochemistry (structure of proteins, lipids, and nucleic acids). A crash course in chemical kinetics and in electrochemistry is provided at the beginning of the course.
Photochemistry studies the action of light on molecules. Understanding photochemistry allows for explaining light-driven phenomena occurring in nature such as vision or photosynthesis; to study cells, materials, or chemical reactions by using fluorophores, imaging agents, or time-dependent spectroscopy; and to develop synthetic light-responsive systems for curing diseases or making solar fuels. Photochemistry is governed by quantum chemistry, excited states, and orbitals. It spans 15 orders of magnitude of time scale range, from femtoseconds for photon absorption to minutes or hours for photoreactions or phosphorescence.
In the PC course basic photochemistry concepts such as excited state multiplicity, photoreaction and emission quantum efficiency, or excited state lifetimes, are first explained. Then, a range of different elementary processes that can follow molecule excitation, are described, including for example emission, non-radiative relaxation, and a range of photoreactions such as electron transfer, energy transfer, or ligand photosubstitution reactions. Two lectures are dedicated to the theoretical modeling of excited states using quantum calculations and the theory of electron transfer (Marcus theory); a computer lab is organized to introduce the students in a practical manner to the representation and modeling of excited states. One course is dedicated to time-dependent spectroscopy for the study of photocatalytic and phototherapeutic compounds. Then, the role of photochemistry in biology is discussed, by a study of vision, followed by the description of Förster energy transfer probes for the study of biomolecules and biological processes. A special lecture is dedicated to photodynamic therapy in cancer treatment, photoactivated chemotherapy, and optogenetics. A last, major part of the photochemistry course is dedicated to the principles of photoredox catalysis and their application for the sustainable production of solar fuels and artificial photosynthesis.
At the end of the course students:
• To understand the concept of excited state and to know the different methods available to represent them
• To manipulate the different elementary processes that can occur following photon absorption by a molecule
• To be able to write the equation describing the kinetics of elementary photochemical processes (photon absorption, transition between excited states, 1st and 2nd order photoreaction)
• To be able to retrieve or calculate quantum yields from experimental data
• To understand double bond photoisomerization reactions and ligand photosubstitution reactions of transition metal complexes
• To interpret time-resolved absorption and emission spectroscopy data
• To know the different methods available to simulate excited states with computers
• To understand energy transfer (Förster, Dexter)
• To understand photoelectron transfer (Marcus theory)
• To know how to study biological processes using photochemistry (bioimaging)
• To know basic concepts for phototherapy and photopharmacology
• To have minimal knowledge about redox potentials in the ground and in the excited state
• To understand charge recombination and how to minimize it
• To understand photocatalytic reactions and mechanisms (oxidative vs. Reductive quenching)
• To understand the basics concept of artificial photosynthesis and solar fuel production
Mode of Instruction
Lectures (10 sessions), exercises (4 sessions), and a computer lab (1 session)
Schedule information can be found on the website of the programmes.
The course is based on the slides presented during the courses and exercises corrected together. The following book is recommended:
Vincenzo Balzani, Paola Ceroni, Alberto Juris (2014) Photochemistry and Photophysics, Concepts, Research, Application, Wiley VCH (ISBN: 978-3-527-33479-7).
Written examination (80%) and computer lab report (20%)
Information about the lecturer
Register for this course via uSis