practical ifsc
The practical course Interfacial Systems Chemistry is a compulsory internship for master
students in the first term of their master studies. Within the framework of the course, students
will gain an overview of the whole field of research and the interdisciplinary research
activities available within the Faculty of Chemistry and Biochemistry and the Research
Department IFSC. One of the central scientific areas researched within the faculty is the
investigation of chemistry on interfaces from molecules to complex systems. Therefore the
name of the internship is related to the name of the research department Interfacial Systems
Chemistry (RD IFSC) established in 2008. The mission of this interdisciplinary research
facility is to pool the competencies in the area of chemistry on interfaces, in order to gain a
deeper understanding of the processes behind it and to achieve a general understanding of
the evolution of chemical complexity. These processes will be investigated using different
approaches, combining synthetical, physical and theoretical chemistry. This internship will
give students an overview of current experimental and theoretical approaches of importance
within, but also beyond, this research focus.
We are offering two experiments:
3. Introduction to Matrix Isolation
Required skills: Basic knowledge on spectroscopy
Short description of the experiment: The spectroscopic detection of reactive intermediates often requires low temperatures and embedding of these molecules in an unreactive environment such as noble gas atoms which form a solid phase at temperatures near absolute zero. This technique is called matrix isolation. In many cases stable precursors are first diluted in the gas phase with a noble gas (argon, neon, nitrogen) and deposited on a cold window and then reactive intermediates can be generated by photochemical means upon irradiation with UV or visible light. The experiments must be performed under a high vacuum to prevent contaminates from unwanted gases freezing to the cold window. Because of the broad optical transparency of the matrix material, the reactive intermediates can be detected by infrared or UV/VIS spectroscopy. By warming up the matrix below the boiling point of the noble gas (“annealing”), the matrix loses rigidity and reactions or the formation of aggregates are possible. This experiment will provide an introduction to this technique. Within the framework of this experiment also quantum chemical calculations will be performed to calculate the geometry and the infrared spectra of simple systems. These theoretical results will be compared to the experimental spectra.
4. Introduction to ESR spectroscopy
Required skills:Basic knowledge about NMR spectroscopy
Short description of the experiment: ESR spectroscopy is a convenient method to study paramagnetic systems such as radicals or high-spin systems (two or more electrons with parallel spin). The benefit of applying ESR spectroscopy here is that it provides a method to selectively detect paramagnetic systems while diamagnetic products do not appear in the spectra. Since organic paramagnetic systems are generally very reactive, ESR spectroscopy is often performed at low temperatures and can be combined with matrix isolation techniques. This experiment will provide an introduction to the theory and technique of ESR spectroscopy by measuring and analyzing ESR spectra of simple paramagnetic systems.
Further reading: A short introduction to ESR spectroscopy can be found in several physical chemistry textbooks and in the dissertation of Hans Henning Wenk (http://www.ruhr-unibochum. de/oc2/dissertations.html , Chapter 2). Additional literature will be provided by the organizers of this experiment.