Prof. Giuseppe Zerbi "The Role of Molecular Dynamics and Vibrational Spectroscopy in the Science of Organic Polyconjugated Systems"

Thanks to  advanced technology  the possibility to explore the properties of materials via infrared and Raman spectroscopy  allows to study peculiar physical phenomena at the molecular level.  In this lecture we  will focused at the class of polyconjugated organic  materials whose properties are modulated by the extent of  delocalization of pi electrons along the molecular chain. First, simple  analytical group frequency spectroscopy combined with normal coordinate analysis  can help in the determination of the chemical structure and architecture of the molecules; then redox reactions (doping) and photoexcitation can be monitored through the infrared spectrum; electron/phonon coupling can be measured with Raman spectroscopy (resonance Raman spectroscopy with various excitation wavelengths).

Of particular interest is the physics associated to the collective totally symmetric Raman active C=C stretching mode which is the only easily accessible tool for understanding many physical properties which are of interest to technology.

The molecular physics  of typical polyconjugated systems will be presented and discussed.