Ateneo - UPO

Ultraviolet spectroscopy (UV)
Infrared spectroscopy (IR)
Nuclear magnetic resonance spectroscopy (NMR)
Mass spectrometry (MS)

R.M. Silverstein, F.X. Webster, Identificazione spettroscopica di composti organici, Casa Editrice Ambrosiana

Additional textbook
M. Hesse, H. Meier, B. Zeeh, Metodi spetroscopici in chimica organica, Edises
H. Günther, NMR spectroscopy, Wiley Ed.

Provide students with the knowledge of the physical principles underlying the different spectroscopic techniques and instrumentation used for the acquisition of spectra. The course is largely devoted to the interpretation of the spectra obtained with different techniques in order to allow the student to master the different spectroscopies especially from the practical point of view, allowing the student to identify unknown organic compounds. The course is complemented by demonstration visits to the various instruments available in the Department.

Knowledge of the structures of the main classes of organic compounds

Lectures with multimedia support and several exercises of structure elucidation. Due to the COVID-19 emergency, in the final part of the course, lessons partly recorded and partly live with MEET, the latter anyway recorded and left available to students.

It will be possible, and highly recommended, to participate to the proposed self-evaluation in-course tests.

Oral test based on the identification of an unknown compound by analysis of IR, NMR and mass spectra, with questions on the theory of the different spectroscopic techniques.

Introduction to spectroscopic methods. Properties of electromagnetic radiation. Electromagnetic spectrum. Absorption and emission spectroscopy.
UV spectroscopy – Molecular energetic levels. Instrumentation. Typical parameters of an absorption spectrum. Electronic transitions and molecular orbitals. Main cromophores. Woodward rules. Law of Lambert-Beer. Uses of electronic spectroscopy. Mention to emission spectroscopy.
Infrared spectroscopy (IR) – Traditional and Fourier transformation (FT-IR) spectrometers. The harmonic oscillator. Non-harmonicity and quantization. Type of vibrations. Instrumentation and sample preparation. The IR spectrum and characteristic absorptions of functional groups. Fingerprints region.
Nuclear magnetic resonance spectroscopy (NMR) – The nuclear spin. Theory of NMR spectroscopy, pulse tecnique and Fourier transformation. Relaxation. Spectral paraneters: chemical shift, spin-spin coupling, integration. 1H NMR: first order spectra. Analysis of main spin systems. Relationship between structure and chemical shift. Symmetry, chirality, dynamic phenomena and NMR spectrum. Spin decoupling and Nuclear Overhauser effect (nOe). 13C NMR: features of 13C nucleus. Decoupled, off-resonance, DEPT e APT spectra. Relationship between structure and chemical shift.
Introduction to main 2D omo- and etheronuclear techniques.
Mass spectrometry – Instrumentation, hints. Chemical and isotopic mass. Mass and electronic parity. Molecular mass and molecular formula determination. Exact mass and resolution. Choice of ionization method for different class of compounds. Fragmentation and rearrangement reactions of the main classes of organic compounds. Spectra analysis and identification of organic compounds from mass spectra. Illustration of the structural determination of a natural substance.

Students must know the main features of the spectroscopies shown. They must also demonstrate to be able to use the knowledge acquired for the structural determination of complex organic compounds by combining in a critical way the various information deducible from the different techniques.