OVERVIEW

This Course deals with the great groups of natural organic compounds (carbohydrates, proteins, lipids, alkaloids) and with the main spectroscopic methods (IR, 1H NMR) to identify the molecular structure of organic compounds.

AIMS AND CONTENT

LEARNING OUTCOMES

Identifying molecular structures of organic compounds by spectroscopic methods.

AIMS AND LEARNING OUTCOMES

Understanding the molecular structure of carbohydrates, proteins and lipids and the chemical properties of monosaccharides.

Understanding the basic principles of organic spectroscopy.

Identifying the molecular structure of organic compounds on the basis of raw formula, infrared (IR) and proton magnetic resonance (1H NMR) spectra.

TEACHING METHODS

Front lessons with (Power Point) slide projection and frequent interaction with the students.

Solving spectroscopy problems in the classroom.

Demonstrations in the IR and NMR laboratories. 

SYLLABUS/CONTENT

CARBOHYDRATES. Monosaccharides: molecular structure of the main compounds, stereoisomerism, steric series, intramolecular reactions producing cyclic forms, mutarotation, reducing sugars, oxidation and reduction reactions, glycosides. Reducing disaccharides: cellobiose, maltose, lactose. Not-reducing disaccharides: sucrose. Polysaccharides: cellulose, starch, glycogen. From the energy of sunlight to the chemical energy of carbohydrates and to cell energy. Recent eco-substainable processes to produce polymers by fermentation of cellulose.

PROTEINS. Amino acids: structure, nomenclature, apolar zwitterionic cationic and anionic forms, isoionic point, electrophoresis. Proteogenic amminoacids: structure, steric series, possible features. Peptides and proteins: primary structure, main kinds of secondary structure (alpha helix or beta-pleated sheet, their rationale and their stabilization), tertiary structure (intrachain interactions, denaturation, fibrous and globular proteins), quaternary structure. Enzymes as catalysts: active sites, key-to-lock interactions, drugs, poisons.

LIPIDS. Hystorical definition. Lipids exhibiting C=C double bonds, or exhibiting alcohol, ketone or carboxylic groups. Glycerides. Importance of the presence of C=C double bonds exhibiting Z configuration in determining the melting points of  fatty acids and glycerides. Waxes. Steroids. Terpenes. Liposoluble vitamins..

ALKALOIDS. Molecular structure of the main compounds.

IDENTIFICATION OF MOLECULAR STRUCTURES. The raw formula and the unsaturation index. The thirteen rule. Electromagnetic radiations. Kinds of molecular energy. When the energy exchange between radiations and molecule takes place. Kinds of molecular spectroscopy. An outline of Visible/Ultraviolet spectrocopy. Coloured compounds. INFRARED (IR) SPECTROSCOPY. The complex molecular vibration and its partial dissection in localized stretching and bending vibrations. The selection rules. The stretching wavenumber as a function of the force constant and the reduced mass. Detailed analysis of the spectral region of functional groups. The fingerprint region. NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY: Magnetic properties of the proton. Magnetic and nonmagnetic nuclei. The magnetic energy levels generated by a strong external magnetic field. The resonance frequency as a function of the magnetogyric ratio, the external magnetic field and the shielding factor. The good separation between the resonance frequencies of the various isotopes. The delta scale, the reference signal and the most used deuterated solvents, The low sensitivityof the method. 1H NMR SPECTROSCOPY. Identification of the exceeding (solvent, moisture, impurities) signals. The number of signals (chemically equivalent and nonequivalent nuclei). The relative intensity of signals. The chemical shift (the contributions of near-by electric currents, of the local electron density and of intermolecular associations). Spin-spin splitting and coupling constants (dependence of vicinal coupling constants on torsion angles, bond lengths, ring size and atom electronegativity)..An outline of Fourier-Transform (FT) spectrometers, of nuclear Overhauser effect and of bidimensional spectra.

General strategy to solve spectroscopy problems.

An outline of the application of spectroscopy to food analysis, medical diagnosis and cultural heritage..

Further details can be found by reading the didactic support in Aulaweb.

RECOMMENDED READING/BIBLIOGRAPHY

Full didactic support can be found in Aulaweb.

For the study of natural organic compounds the same book used for Organic Chemistry part 1 can be of additional help.

TEACHERS AND EXAM BOARD

Exam Board

LARA BIANCHI (President)

MASSIMO MACCAGNO

RENATA RIVA

CINZIA TAVANI

LESSONS

Class schedule

ORGANIC CHEMISTRY 2

EXAMS

Exam schedule