PHOTOCHEMISTRY
Academic year and teacher
If you can't find the course description that you're looking for in the above list,
please see the following instructions >>
- Versione italiana
- Academic year
- 2017/2018
- Teacher
- MARIA TERESA INDELLI
- Credits
- 6
- Curriculum
- CHIMICA, MATERIALI ED ENERGIA
- Didactic period
- Primo Periodo Didattico
- SSD
- CHIM/03
Training objectives
- The course gives a comprehensive view of the processes involving light and chemical systems, from simple molecules, to complex supramolecular systems, to specific biological systems. The basic knowledges that the student must learn are the description of electronically excited states and of the main physical and chemical unimolecular processes that lead to their deactivation; the main bimolecular processes of excited states with particular emphasis on energy and electron transfer, the mechanisms of important photoinduced processes in biological systems, such as photosynthesis and vision. Finally, perspective applications of supramolecular photochemistry are introduced, including solar energy conversion, molecular electronics and photonics. On the basis of these fundamentals,the students must be able to interpret photophysical and photochemical processes that are on the basis of natural and artificial systems in the field of solar energy conversion.
Prerequisites
- Basic notions of inorganic chemistry, quantum chemistry and spectroscopy.
The background knowledges provided by the courses of Physical Chemistry are mandatory. Course programme
- The course forecasts 32 hours of frontal lectures concerning the following topics:
Electronic states. Born-Oppenheimer approximation. MOs, electron configurations, states. Vibrational levels.
Light absorption. Transitinon moment. Selection rules: symmetry and spin. Franck-Condon principle. Structure of absorption bands.
Radiative deactivation. Vibrational relaxation. Fluorescence and phosphorescence. Franck-Condon factors and absorption/emission relationships. Excited-state distortion and Stokes shift. Radiationless transitions. Fermi golden rule. Internal conversion and intersystem crossing. Franck-Condon factor. Energy-gap law, deuteration effects. Intersections and avoided crossings.
Chemical processes in excited states. Correlation diagrams for molecular orbitals and states. Dissociation of sigma bonds; Twisting around "pi" bonds. Pericyclic reactions.Photosubstitution in octahedral metal complexes.
Bimolecular excited-state processes. Stern-Volmer kinetics. Electronic energy transfer. Spectral overlap. Coulombic and exchange mechanisms. Quenching and sensitization. Photoinduced electron transfer. Redox properties of excited states. Kinetic models. The inverted region. Charge separation and recombination. Chemluminescence.
Photochemistry in biological systems. Photons as energy quanta and infromation bits. Photosynthesis. General aspects of solr energy. Types of conversion. Natural photosynthetic membranes. Antennae. Reaction centers. Architecture, thermodynamics, kinetics. Vision. Photoreceptors, Primary photoprocesses. Photochemistry in artificial supramolecular systems. Nanometric molecular devices. Top-down and bottom-up approaches. Towards artificial photosynthesis. Artificial reaction centers and antennae. Photovoltaic and optoelectronic devices. Dye sensitized semiconductor photoelectrochemical cells.
Practice lessons (24 hours, 2 credits): laboratory experiments concerning the main topics of the course Didactic methods
- The course is constituted of 4 credits of frontal lessons, with the help of slides wich help explaing the different subject and 2 credits of laboratory.
Learning assessment procedures
- The aim of the exam is to verify the knowledges and the abilities of the basic formation and at which level the learning objectives previously described have been acquired. The exam is oral and involves at least 3 questions.
There are two exam sessions (december-february and june-september). Each session includes 3-5 exam dates. Reference texts
- Teacher's handhouts and the following textbooks:
"Photochemistry and Photophysics, Concepts, Research, Applications" V. Balzani, P. Ceroni, A. Juris, Wiley-VCH,Verlag 2014
"Supramolecular Photochemsitry" V. Balzani, F. Scandola, Horwood, 1991
