58034 - Organic Chemistry Laboratory

Learning outcomes

The course aims to enable students to carry out a simple organic reaction based on a known procedure, taking into account the safety regulations. They should be able to perform the standard separation and purification procedures (crystallization, distillation, liquid-liquid extraction, chromatographic columns) commonly used in the organic chemistry laboratory. Students will acquire basic knowledge of some spectroscopic and spectrometric techniques (i.e. mass spectrometry and IR spectroscopy) for the identification of functional groups and the complete structure of organic molecules.

Course contents

General Description

Introduction to standard glassware equipment commonly used in organic synthesis. Introduction to Thin Layer Chromatography (TLC) and purification techniques including crystallization, distillation, and solvent extraction. Basic analytical techniques for organic chemistry such as melting point determination, IR spectroscopy, NMR spectroscopy, HPLC and GC chromatographic techniques, and polarimetry for the determination of optical rotation. Identification of an unknown compound through a complete characterization.

Detailed Description

Safety in the Organic Synthesis Chemistry Laboratory Introduction to laboratory safety procedures, focusing on appropriate working practices in an organic synthesis laboratory. Use of organic solvents and proper disposal of all laboratory waste.

Glassware and laboratory equipment. Overview of glassware commonly used in an organic chemistry laboratory, demonstration of specific uses for each, and selection of appropriate glassware. Use of rotary evaporators, vacuum systems, balances, and other standard equipment.

Design and execution of a chemical reaction. Discussion of optimized procedures for the synthesis of simple organic compounds, focusing on stoichiometry, solvent selection, and appropriate equipment for the synthesis, purification, and characterization of the compound.

Lab notebook and reports. How to prepare a laboratory notebook, its purpose and the information it must contain; how to prepare a laboratory report, its purpose, content, realization; definition, calculation, and evaluation of reaction conversion and yield.

Techniques for the identification of organic compounds: thin layer chromatography, polarimetric analysis, and melting point.

Analytical techniques: Determination of optical rotation. Which class of molecules can be analyzed; equations for determining α rotation; sample preparation for analysis; description of instrument geometry and operating steps for analysis; processing of experimental data for α rotation calculation.

Purification techniques: flash chromatography. Fundamentals; mobile phase and stationary phase; non-covalent interactions of solutes with the stationary phase; mobile phase selection criteria; eluent performance and selectivity; column preparation and selection; dry and wet conditioning; sample preparation and loading.

Analytical techniques: Determination of melting point. Identification of suitable substances to be used for this characterization; sample preparation; instrument description; polymorphism notes.

Spectroscopic identification: Introduction to mass spectrometry. Electron Spray Ionisation; main features of an ESI mass spectrum; positive and negative scans (ESI+ and ESI-); characteristic mass peaks and interpretation of HPLC-MS and GC-MS analysis. Electron Impact Ionisation; features of an EI mass spectrum; molecular peak; base peak and fragmentation peak.

Spectroscopic identification: Applications of UV spectroscopy in organic chemistry. UV absorption bands; chromophores; effects of unsaturation; examples of spectra.

Spectroscopic identification: Nuclear magnetic resonance. Introduction to instrumentation; assessment of risks associated with the presence of liquid gases for cryomagnet maintenance; definition of shielding and chemical shift; parameters affecting chemical shift: electronic, molecular, and solvent; 13C and 1H chemical shift scales, detailed discussion: examples and interpretation of spectra; main classes of organic compounds and characteristic chemical shifts.

Readings/Bibliography

R.M. Roberts, J.C. Gilbert, S.F. Martin "Chimica Organica Sperimentale" Zanichelli Editore, 1999.

R. M. Silverstein, F.X. Webster, D.J. Kiemle "Identificazione spettrometrica di composti organici" Terza edizione. Casa Editrice Ambrosiana, 2016.

M. D’Ischia “La chimica organica in laboratorio. Laboratorio, composti organici, metodi e tecniche sperimentali” Piccin, 2003.

Teaching methods

• Taught class
• Group activities
• Laboratory activities

Due to the nature of the activities and teaching methods used, participation in this training activity requires all participants to complete Modules 1 and 2 in e-learning mode and to attend Module 3 for specific training on health and safety at work. Information on dates and methods of attendance for Module 3 can be found in the specific section of the course website.

Assessment methods

Assessment for Modules 1 and 2 in the laboratory will be unified and expressed by a qualifying examination. Assessment will be based on

• Preparation of final reports relating to laboratory activities
• Adherence to safety regulations
• individual student preparation and skill
• Completion and management of the laboratory notebook
• Respect of the deadlines for the submission of the reports

There is no final examination.

Attendance of at least 75% of the classroom and laboratory activities is required to complete the course. A positive assessment of at least 75% of the reports is also required.

Teaching tools

The teaching materials used in class will be available on the Virtuale platform immediately after the class is completed.

Office hours

See the website of Matteo Di Giosia

See the website of Lucia Ferrazzano