The course provides to the students the skills for the structural and conformational characterization of organic compounds, through the application of nuclear magnetic resonance and mass spectrometry.
Expected learning outcomes
The course provides to the students an advanced knowledge of NMR and mass spectroscopy, Eventually, students will be able to interpret mono and two-dimensional NMR spectra (1H-NMR and 13C-NMR) and mass spectra of organic molecules.
NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY Description of the technique and of spectral parameters: · chemical shift and factors causing the variation of chemical shifts · coupling constants and signal multiplicity. Origin of splitting. · NMR applied to hetero-nuclei and their peculiarities in the observation of the NMR spectra Homo- and hetero nuclear decoupling. Relaxation times. Nuclear effect Overhauser (nOe). Dynamic spectroscopy. Pulse experiment: the spin echo experiment as an introduction to one-dimensional pulsed sequences. 13C-NMR spectroscopy. One-dimensional experiments (1D) with complex pulse sequences: JMOD, INEPT, DEPT. Multidimensional spectroscopy. The NMR experiment in two dimensions (2D). Homonuclear experiments: COSY, TOCSY, and NOESY. Heteronuclear experiments: 1H-13C HSQC. Applications of Nuclear Magnetic Resonance to the conformational analysis of organic molecules. Interpretation of 1H and 13C-NMR spectra.
MASS SPECTROMETRY Description of the technique and of the instrumentation. Use of mass spectrometry in the structural determination of organic molecules. Insights in the main types of ions, in the factors influencing the fragmentation of ions and in the types of fragments. Fragmentation in the main classes of organic substances. Insights in the use of different types of instruments for the study of different classes of molecules. Mass spectrometry combined with chromatography.
Classroom exercises for the structural determination of unknown molecules through the interpretation of NMR and mass spectra.
Prerequisites for admission
Skills in organic chemistry Basic skills in Nuclear Magnetic Resonance and Mass Spectrometry
Lectures and exercises
- R. M. Silverstein, F. Webster, "Identificazione Spettroscopica di Composti Organici", Casa Editrice Ambrosiana, Milano. - H. Friebolin, Basic One- and Two-Dimensional NMR Spectroscopy, VCM. - M E. Rose,R. A. W. Johnstone, Mass Spectroscopy for Chemists and Biochemists, Cambridge University Press.
Assessment methods and Criteria
The assessment is a written test with question about the theory and exercises. The theoretical part includes questions on the topics developed in the course, to assess the student's knowledge on the theoretical aspects of the subject. In the applicative part, the student has to analyze a set of 1H and 13C NMR spectra (mono and bidimensional) obtained from an unknown compound and /or a known structure. Furthermore, in the practical part, fragmentation peaks in a mass spectrum of simple organic molecules should be analyzed. The exam will last about two and a half hours.