OVERVIEW

The 5-credits course for Chemistry and Chemical Technologies (L-27) deals with the great groups of natural organic compounds (carbohydrates, proteins, lipids, nucleic acids) and with the main spectroscopic methods (IR, 1H NMR, MS) to identify the molecular structure of organic compounds.

The 4-credits course for Materials Science (L-30), Methodologies for Conservation of Cultural Heritage (LM-11) or other courses, deals only with the main spectroscopic methods (IR, 1H NMR, MS).

AIMS AND CONTENT

LEARNING OUTCOMES

The course aims to provide students with the basic knowledge on the main natural organic substances and the knowledge necessary for the identification of simple organic molecules through the use of the most widely used spectroscopic methods in Organic Chemistry.

AIMS AND LEARNING OUTCOMES

Understanding the molecular structure of carbohydrates, proteins and lipids and the chemical properties of monosaccharides (only for students with 5 CFU)

Understanding the basic principles of organic spectroscopy.

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

PREREQUISITES

The knowledge of a fundamental course of organic chemistry is a prerequisite

TEACHING METHODS

Front lessons with (Power Point) slide projection. The lessons wil, be recorded and will be made available only to those students who have objective reasons that impede frequency (e.g. students who also work).

Practical exercises will be carried out in small groups in a classroom and the frequency is mandatory. If the students are more than 20-25, they will be divided into groups, which will attend these excercise in different hours/days.

The module consists of 5 CFU, 44 hours divided as follows: 32 h of theoretical lessons and 12 h of classroom exercises.

For SCIENZA DEI MATERIALI (L-30) and METODOLOGIE PER LA CONSERV. RESTAURO BENI CULTURALI (LM-11), the course consists of 4 CFU, 36 hours divided as follows: 24 h of theoretical lessons and 12 h of classroom exercises.

All the lessons and exercises for the spectroscopy section will be held during the second semester. Only the students with 5 credits will have lessons during the first semester (8 hours, on natural substances).

SYLLABUS/CONTENT

NATURAL SUBSTANCES (8 hours) (only for students with 5 credits)

CARBOHYDRATES. Monosaccharides: molecular structure of the main compounds, stereoisomerism, steric series, cyclic forms, mutarotation, reducing sugars, oxidation and reduction reactions, glycosides. Reducing disaccharides: cellobiose, maltose, lactose. Not-reducing disaccharides: sucrose. Polysaccharides: cellulose, starch, glycogen, chitin. 

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, quaternary structure. 

LIPIDS. Triglycerides: structure and properties. Saponification. Waxes. Phospholipids. Terpenes and steroids (hints). 

NUCLEIC ACIDS. Nucleosides and nucleotides. Nitrogen bases. DNA and RNA. Genetic mutations.

IDENTIFICATION OF MOLECULAR STRUCTURES.

MASS SPECTROMETRY. Calculation of unsaturation sites. General concepts. Isotopic peaks. Overview of possible fragmentations of organic molecules after electron impact (EI) ionization. 

INFRARED (IR) SPECTROSCOPY. The complex molecular vibration and its partial dissection in localized stretching and bending vibrations. The stretching wavenumber as a function of the force constant and the reduced mass. Detailed analysis of the most typical bands of functional groups.

NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY: Magnetic properties of the proton. 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 delta scale, the reference signal and the most used deuterated solvents, the low sensitivityof the method. An outline of Fourier-Transform (FT) spectrometers. 1H NMR SPECTROSCOPY. Topology of protons (homotopic, enantiotopic, diastereotopic and constitutional different) and hence how to determine the number of signals (chemically equivalent and nonequivalent nuclei). Use of signal integrals. The chemical shift (the contributions of near-by electric currents, of the local electron density and of intermolecular associations). How to predict chemical shift  also with the use of parametric equations. Spin-spin coupling. How to predict the multiplicity of signals. The utility of coupling constant.  Second order multiplets. Systems simpler than expected. The case of NH and OH groups. Hints on NMR of other nuclei (especially 13C). In the last 2 hours, the teacher will show how to solve exercises analogue to those proposed during the exam,

EXERCISES. The students will be guided through exercises of increasing complexity in order to become able to predict a spectrum from the formula and eventually to guess an unknown formula from a series of provided spectra

RECOMMENDED READING/BIBLIOGRAPHY

For the spectroscopy section (these books are available also in english)

• Identificazione spettrometrica di composti organici, Robert M. Silverstein, Francis X. Webster, Ambrosiana
• Metodi spettroscopici in chimica organica, Manfred Hasse, Herbert Meier, Bernd Zeeh, Edises

For the natural substances section: anyone of these books (most of them are also available in english)

• J. McMurry, CHIMICA ORGANICA, Piccin
• P.Y. Bruice, CHIMICA ORGANICA, EdiSES
• M. Loudon, CHIMICA ORGANICA, EdiSES
• P.C. Vollhardt, N.E. Schore, CHIMICA ORGANICA, Zanichelli
• A.A. vari, CHIMICA ORGANICA (a cura di B. Botta), Ediermes
• Brown-Foote-Yverson-Anslyn, CHIMICA ORGANICA, Edises

Anyway, all the slides will be made available in advance on aulaweb

LESSONS

LESSONS START

The natural substances section will start around late november. The exact date will be communicated later. The spectroscopy part wil, be entirely in the second semester and will start according to the calendar of the course.

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

The exam will be written and oral. The oral will be done typically 2 days after the written exam. The written and oral part must be taken in sequence. If a student fails the oral, he/she has to repeat the whole exam in the next session.

The written exam will have two parts. In the first one there will be 10 questions with multiple answers. Every right answer will count up to 3 points and every wrong answers 0 points.

In the second part the students will receive the MS, IR and NMR spectra and selected MS data of 2 unknown substances. They must try to recognize the molecules and write a report detailing the reasoning made. They also must report in synthetic form the complete NMR data and justify some selected peaks of MS and IR spectra.

In order to be admitted to the oral, students must get 17,5 points (out of 30) in the first part. For the second part they will be surely admitted if they recognize the formulas. However, even if they do not succeed in recognizing the correct formulas, if the reasoning made in the report seems sound, they will be admitted anyway. A blank report means no admission.

The oral part will entail:

a) Discussion of the spectrometry excercises

b) 1-2 questions on the course syllabus.

Obviously the questions of written and oral exam will depend on the credits of each students. Students with 4 credits will not encounter questions on natural substances.

ASSESSMENT METHODS

The first part of the written exam will assess if the students have understood the concepts of the course.

The second part of the written exam will evaluate the ability of the student to use theoretical notions to identify the structure of an organic molecules, given the molecular weight or the chemical formula and the IR, MS and 1H-NMR spectra.

The oral exam will mainly focus on the topics covered during the lessons and will aim to assess the achievement of the appropriate level of theoretical knowledge. The ability to present the topics clearly and with correct terminology will also be evaluated, as well as the ability to write formulas and equations.

The final grade will not be an automatic average of the grade of written and oral exam. The teacher will take into account the capacity of the student to reason on the spectra received, and that will be assessed either during the written or oral exam.

FURTHER INFORMATION

Ask the professor in charge for other information not included in the teaching schedule.

Students who have valid certification of physical or learning disabilities on file with the University and who wish to discuss possible accommodations or other circumstances regarding lectures, coursework and exams, should wr5ite an E-mail both to the instructor and with Professor Sergio Di Domizio (sergio.didomizio@unige.it),the Department’s disability liaison. This E-mail should be better sent 10 days before the exam. If the disability reference person confirms that a valid certification has been provided, students will have an additional time for the written exam (30% more for LSD and 50% for disability): Moreover, the students may use a calculator and use "concept maps". However, concept maps must be preventively examined and approved by the instructor.