Corso di laurea magistrale in Chimica dell'Ambiente

The purpose is to present to the students an overview of the most important reactions that take place in the troposphere and stratosphere, both organic and inorganic. Their impact onto the climate, air quality, and human health is also discussed. Also some aspects of the "Green Chemistry" are presented. Information on the atmospheric reactions mechanisms is given (with a part dedicated to combustion processes). How field studies, experimental laboratory investigations, and theoretical-modelistic studies are intertwined is stressed, as the reach and limits of different methods of investigation. Through their lab work, the students acquire confidence on the last aspect, by carrying out quantum mechanical computations on simple reaction pathways.

The student is expected to attain an overall knowledge of the complex relation among different organic reactions that take place in the atmosphere, involving organic species of anthropogenic or natural origin. A gas-phase chemistry is mainly discussed. However, some cases of heterogeneous chemistry are also presented, since the transition from molecular clusters to particulate is considered, in particular the carbonaceous particulate. Its affinity with some organic molecules induces to discuss reactions which can take place at the gas-solid interphase.

An overview of atmospheric problems. Vertical structure of the atmosphere. Irradiation and photolysis. Kinetic analysis af the data. Natural lifetime and half-lives. Dependance of the reaction rate from T and P. Arrhenius equation. Transition State Theory. Diurnal and nocturnal oxidation of methane and carbon monoxide. HO_x cycles. Alkane oxidation. Alkyl, Alkyl peroxyl, and alkoxyl radicals. Reaction channels and branching ratios. Oxidation of alkenes triggered by HO and NO₃. Ozonization of alkenes. Oxidation of alkynes. Experimental and theoretical studies on the reaction mechanism. Oxygenated compounds. Aromatic hydrocarbons. Kinetic studies on the oxidative degradation. Some information on theoretical studies of the oxidation mechanism. Polycyclic Aromatic Hydrocarbons (PAH) and their association with the atmospheric particulate. Photolysis and oxidation (functionalization) by HO, NO₃, O₃, etc. Aerosol. Multimodal nature of the atmospheric particulate. In particular, origins, composition and role of the carbonaceous particulate. Chemistry of the stratosphere. Transport of pollutants from troposphere to stratosphere. The Chapman cycle and the "ozone hole". Other cycles. Green chemistry: principles and applications (dimethyl carbonates, ionic liquids and DES, supercritical fluids, perfluorinated compounds, microwaves, water). Examples from the recent literature.  Combustion: types of flames, H₂/O₂ reaction, low and high-temperature mechanisms of CH₄ andC₆H₆ oxidation at low and high-temperature, equilibrium, partial equilibrium, quasi-steady state approximation, NO and CO₂ formation.
Introduction to the lab work: theoretical tools, programs, model systems to be studied as regards reaction mechanisms. Lab work.

Lessons (6 credits, i.e. 4 of lessons and 2 in the lab). To attend the lectures is not mandatory, just advisable. The attendance to the lab is compulsory.

The course is held in presence.
The didactic material is published on Moodle platform.  

Communication with students: teacher is available to answer questions by email or, on request, by meeting on Webex.

The oral examination has the purpose of assessing how clear are the concepts to the student, and how clearly she/he can discuss the proposed theme. Organic reactions in the atmosphere typical of certain classes of compounds (alkanes, alkenes, alkynes, aromatic hydrocarbons, etc.) have to be discussed, taking also into account kinetic and photochemistry aspects. How these organic reactions are intertwined with the evolution and action of reactive inorganic species is also considered. The oral examination is believed to allow the assessment of the logic capabilities of the student, more than a written test. Two or three questions are usually posed. A Moodle quiz on the treated experiences is required at the and of the laboratory. The total vote will be average weighted with the oral examination. Grades are expressed in /30^th.

The exam will be held in precence.

Not contemplated.

1. B. J. Finlayson-Pitts, J. N. Pitts "Chemistry of the Upper and Lower Atmosphere", Academic Press, 2000.

2.  H. Akimoto, "Atmospheric Reaction Chemistry", Spinger, 2016.
Ebook available: https://link.springer.com/book/10.1007/978-4-431-55870-5

To attend the lectures is not mandatory, just advisable. The attendance to the lab is compulsory.

Students with DSA or disabilities are kindly requested to familiarize themselves with the support procedures (https://www.unito.it/servizi/lo-studio/studenti-con-disabilita and https://www.unito.it/accoglienza-studenti-con-disabilita-e-dsa) at the University, especially the necessary procedures for in-exam support (https://www.unito.it/servizi/lo-studio/studenti-con-disabilita/supporto-agli-studenti-con-disabilita-sostenere-gli-esami).