18167 - Organic Chemistry Principles

Learning outcomes

At the end of the course the student acquires basic knowledge of the structure of matter and of the thermodynamic and kinetic principles that govern its transformation, as well as the fundamental skills for understanding the relationships between structure, properties and reactivity of organic molecules, with particular reference to the molecules of interest in the food. At the end of the course student is able to understand, at the molecular level, the chemical reactions that occur in the biosphere, as well as to predict the behavior of a molecule as a function of its structure.

Course contents

Prerequisites

What is taught in the General and Inorganic Chemistry course and in the preparatory courses. In particular: atoms and their periodic properties; ionic and covalent chemical bonds and their effect on the stability of molecules; structure of molecules and chemical formulas; the concept of mole; reactions and balancing of chemical equations; chemical thermodynamics and dynamic equilibria; solutions and solubility; acid/base balances; oxidations; speed of reactions and effect of temperature.

Contents of the theoretical didactic unit (36 hours)

1. Review of general chemistry (The electronic model of the atom; Theory of atomic orbitals; Energy and shape of atomic orbitals; Arrangement of electrons in atomic orbitals; Bonds between atoms; electronegativity; Inverse relationship between bond distance and bond strength ; Oxidation number, formal charge, charge separation. Resonance limit structures)

2. Alkanes: nomenclature of linear, branched and cyclic alkanes).

3. Alkenes and Alkynes: nomenclature. Notes on thermodynamics. Stability of alkenes linked to resonance, hyperconjugation or electric charge density. Verification of relative stability through reactions carried out inside calorimeters.

4. Stereochemistry. Definition and geometric considerations on isomers, which can be divided into structural isomers and stereoisomers, the latter can be divided into enantiomers and diastereoisomers. Nomenclature of R-S chiral centers. Cis-trans nomenclature. Chemical and physical properties and interaction with polarized light of enantiomers and diastereoisomers. Meso compounds and racemic mixtures. How to derive the chirality of a chiral carbon of a molecule written according to the Fisher convention.

5. Intermolecular bonds to evaluate the correlation between characteristics of organic molecules and their melting and boiling points. Correlation between the characteristics of a molecule and its stability: the case of cyclic molecules.

6. IUPAC and traditional systematic nomenclature of alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, amines, thiols and thioethers. Carbonyl and carboxyl groups.

7. How the acid-base properties of a molecule are influenced by the presence of functional groups, by its structure, by the hybridization of its atoms. The student must be aware of which substance gives rise to the most stable cations and anions and must be able to provide an interpretation of this experimental data. Tautomeries.

8. Benzene and aromaticity: description of the phenomenon of aromaticity - benzene derivatives - resonance in benzene derivatives - conjugative and inductive effects of the substituent groups - effect of the substituent on the acid-base properties of some aromatic molecules. Exercises on acidity and basicity of substances: inductive and conjugative effect exerted by the phenyl group and any substituents present on it.

9. Groups containing C=O: nomenclature and properties of carboxylic acids, aldehydes, ketones, carboxylic acids and esters, soaps and detergents, fats and oils. The student must know what the resonance limit structures are necessary to understand the reactivity of this functional group.

10. Chemical reactions. Nucleophilic addition to carbonyl carbon. Nucleophilic substitution at the carboxyl carbon. Acid and basic hydrolysis (saponification) of esters. Electrophilic addition of hydrogen halide and molecular bromine to alkenes. Formation of alcohols from alkenes. Electrophilic substitution at the benzene ring. Nitration. Sulfonation. Electrophilic substitution at the substituted benzene ring. Activating, deactivating, ortho-para orienting and meta orienting. Nucleophilic substitution at saturated carbon (sn1 sn2).

Contents of the laboratory (18 hours)

The student will be given explanations in the classroom on how it is useful to set up an experiment in the laboratory to highlight particular properties of a substance or sample of interest. The aspects on which attention will be focused will be the acid-base properties of the substances, the inductive and conjugative effect of the functional groups. In the laboratory, the student will separate some nitroanilines using thin layer chromatography (TLC), perform an esterification according to the method developed by Fisher, and concentrate the aromatic substances of a cherry flavored cola.

Contents of the in-depth didactic unit (6 hours)

Students who follow organic chemistry lessons are typically uneven in terms of basic knowledge and aptitude for the study of scientific-technological disciplines. Some lesson hours of the second teaching unit were expressly designed to help those who found it more difficult to follow the lessons of the first teaching unit. These hours, in fact, will be dedicated to requests for clarification from students on the topics covered in the first teaching unit. The requests may concern mere repetitions of what has already been explained, exercises aimed at better understanding the proposed topics or in-depth analysis of any aspect of organic chemistry or similar subjects of interest to the students. The content of these lessons will therefore not be determined in any way by the teacher, but will be decided independently by the students.

Readings/Bibliography

I strongly recommend that you equip yourself with Wade, "Fundamentals of organic chemistry", Piccin and to consider it the reference point as teaching material, to be read in its entirety, in the chapters covered in class, and to be consulted assiduously, together with your own (and not someone else's) notes taken in class.

The reason is that "Fundamentals of Organic Chemistry" textbooks are typically equivalent in terms of subject matter and level of coverage. However, some authors seem more sensitive to the difficulties of students in many science courses, and have adapted their texts accordingly.

Other very valid books, although set in a more classical way, are the following:

Solomons, "Fundamentals of organic chemistry", Zanichelli.

McMurray, "Fundamentals of organic chemistry", Zanichelli.

Teaching methods

The course is divided into three teaching units:

The first, theoretical, consists of frontal lessons accompanied by exercises to apply the concepts presented.

The second teaching unit includes laboratory activities aimed at deepening some aspects of the topics covered in class from an experimental point of view. The laboratory activities therefore aim at making students acquire the typical learning method of organic chemistry, i.e. the ability to translate a concrete problem into chemical language in order to determine its solution.

Some lesson hours of the second teaching unit will be dedicated to requests for clarification from students on the topics covered in the first teaching unit. Requests may concern mere repetitions of what has already been explained, exercises aimed at a better understanding of the topics proposed or in-depth studies on any aspect of organic chemistry or related subjects of interest to students. The content of these lessons will therefore not be determined in any way by the teacher, but will be decided independently by the students.

The third didactic unit will aim to describe, with the active involvement of students, IT tools useful for laboratory data processing at a professional level. The teacher will show what is necessary in the computer room, where the students will find dedicated freeware software pre-installed onto their computers.

Assessment methods

During the oral exam, the student will address the topics covered in class, all available in the recommended texts, and also the notions of General Chemistry essential for the knowledge of Organic Chemistry. The student will be assessed on the basis of the following criteria: (i) knowledge, understanding and in-depth analysis of the topics covered; (ii) critical and expository ability; (iii) correctness of technical-scientific language. The oral exam may have a maximum score of 30 points, possibly with honors. Educational gaps and/or inappropriate language - even in a context of minimal knowledge of the exam material - will lead to an insufficient grade.

The appeals are proposed within the specific windows defined within the Course of Study and students can book for the oral exam exclusively using the methods provided by the Alma Esami online system. For any information on the booking methods, connect to the "almaesami" application.

Teaching tools

The teacher does not use slides to support oral explanations, but writes on paper, which he shows to the entire classroom via video camera. This modality, which has received wide acclaim in the evaluation of teaching, favors learning by imitation, which in organic chemistry is at least as important as the notional one.

For further support, the teacher uses the textbook directly, so that he passes even better the concept that studying on it is fundamental. In fact, the teacher has chosen it carefully so that it fits in remarkably with the proposed course and addresses the issues as he deems necessary.

Office hours

See the website of Luca Laghi