73057 - Methods of Structural Characterization

Learning outcomes

The main aim of the course is to provide a description of theoretical and experimental aspects of: 1) Nuclear magnetic resonance spectroscopy (NMR); in particular, the basis of the theory of pulsed NMR will be explained, the 1D and 2D NMR experiments will be described and their applications for the determination of a complex structure. 2) Mass spectrometry; in particular, the ionization techniques to determine the mass of macromolecules. Also other important aspects will be examined such as molecular recognition, a phenomenon which is the basis of many vital processes.

Course contents

Nuclear Magnetic Resonance:

a) Nuclear spin and resonance. The vector model: Zeeman effect. Precession. Spin states. Larmor frequency. The laboratory and rotating frames of reference. Pulses. Free Induction Decay (FID). Chemical shifts and the shielding constants. Fourier trasform. The spectrometer.

b) Spin relaxations: T1 and T2. Measures of T1 and T2. Spin-echo. Diagnosis techniques: MRI and MRS in vivo. Solvent suppression.

c) Scalar coupling constants.

d) Heteronuclear NMR. APT experiment. Polarization Transfer: INEPT and DEPT experiments.

e) 2D NMR: COSY, HETCOR, HSQC, HMQC, HMBC.

f) NOE Effect. Steady-state NOE, transient NOE, NOESY. Spin-locking, TOCSY and ROESY.

g) Dynamic NMR.

h) Mentions of NMR of peptides and proteins.

i) Mentions of HR-MAS NMR and DOSY.

Mass Spectrometry

a) Ionization Tecniques: Electron Ionization and Chemical Ionization. Mass analyzers: magnetic sectors, quadrupolar analyzer, FT-ICR, time of flight (TOF). Ion detector.

b) Ionization Tecniques of macromolecules by desorption: elettrospray ionization (ESI-MS), Atmospheric pressure chemical Ionization (APCI) ( Matrix-Assisted Laser Desorption Ionization (MALDI). Fast Atom Bombardment (FAB).

c) GC-MS, HPLC-MS, Tandem Mass Spectrometry (MS-MS). Peptide and protein analysis.

Readings/Bibliography

'High-Resolution NMR Techniques in Organic Chemistry'

T. D. W. Claridge

Pergamon Press 1999

'Identificazione spettrometrica di composti organici'

R. M. Silverstein, F. X. Webster, D. J. Kiemle, D. L. Bryce

3a Ed., Casa Editrice Ambrosiana 2016

'Mass Spectrometry fo Biotechnology'

G. Siuzdak

Academic Press 1996

Teaching methods

Theroretical lessons

Assessment methods

Oral examination. A description of the basis on which the various instrumental techniques are founded and their use in solving chemical problems are required.

Teaching tools

Powerpoint slides

Office hours

See the website of Elisabetta Mezzina