18039 - Structural Characterization of Organic Compounds

Course Unit Page

SDGs

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.

Good health and well-being Clean water and sanitation Affordable and clean energy

Academic Year 2018/2019

Learning outcomes

Aim of the course is to provide the student with the knowledge necessary to identify and characterize an organic compound by using spectroscopic techniques.
In order to follow profitably the course the student must know the basic principles of organic chemistry as well as of physics.

Course contents

Quantization of the energy levels of atoms and molecules. Absorption of electromagnetic radiations by molecules.
UV and visible spectroscopy. Beer-Lambert law. Electronic transitions and Molecular Orbitals. Absorbing groups: polyenes, aromatic rings, carbonyl compounds. Substituent and solvent effects on electronic transitions. Structural information from UV and visible spectra. Applications.
Linear and circular dichroism: outlines.
Fluorescence spectroscopy. Excited electronic states and Jablonski diagram. Fluorescence and phosphorescence. Applications.
Infrared spectroscopy. Harmonic and anharmonic oscillators. Selection rules for vibrational transitions. Group frequencies and analysis by IR.
Nuclear Magnetic Resonance. Zeeman interaction between nuclear spin and magnetic field. Spin-spin coupling. NMR spectra of AX and AB systems. First order spectra. Chemical shift and chemical structure. Factors determining the magnitude of the spin-spin coupling constants. Interpretation of simple proton NMR spectra.
Carbon-13 NMR spectra. The sensitivity in NMR spectroscopy. Pulsed NMR and Fourier transform. Proton decoupling. Chemical shift of carbons. Applications.
Mass spectrometry. Principles and outlines of instrumentation. Ionisation by electron impact and chemical ionisation. Mass analysers. Molecular ion and isotopomers. Modes of fragmentation. Fragmentation of common functional groups.

Readings/Bibliography

G.F. Pedulli, Metodi Fisici in Chimica Organica, Piccin Editore.

Silverstein, Webster, Kiemle, Bryce, Identificazione spettrometrica di Composti Organici. Casa Editrice Ambrosiana

Teaching methods

Lectures and training lessons

Assessment methods

Solution of an exercise consisting in the identification of an unknown substance on the basis of the IR, UV, proton and 13C NMR, and Mass spectra. 
Written exam on the theoretical and practical aspects of the various spectroscopic techniques.

Teaching tools

PowerPoint slides

Office hours

See the website of Marco Lucarini