Unit SPECTROSCOPIC METHODS FOR ORGANIC AND BIOORGANIC MOLECULES
- Course
- Chemical sciences
- Study-unit Code
- A002018
- Curriculum
- In all curricula
- Teacher
- Oriana Piermatti
- Teachers
-
- Oriana Piermatti
- Hours
- 47 ore - Oriana Piermatti
- CFU
- 6
- Course Regulation
- Coorte 2022
- Offered
- 2022/23
- Learning activities
- Caratterizzante
- Area
- Discipline chimiche organiche
- Academic discipline
- CHIM/06
- Type of study-unit
- Obbligatorio (Required)
- Type of learning activities
- Attività formativa monodisciplinare
- Language of instruction
- Italian
- Contents
- Mass spectrometry (MS): Introduction and fundamental concepts. The MS spectrometer. EIMS spectrum analysis: types of ions generated, schemes of fragmentation and rearrangements.
Infrared spectroscopy (IR): Introduction and fundamental concepts. IR spectrophotometers. IR spectrum regions and characteristic absorptions of the main functional groups.
Nuclear magnetic resonance spectroscopy (NMR): fundamental concepts, magnetic properties of nuclei.
- 1H NMR spectroscopy: chemical shift, spin-spin coupling, chemical and magnetic equivalence, selective spin decoupling, nuclear overhauser effect (NOE).
-13C-NMR spectroscopy: chemical shift, broadband decoupled spectra, heteronuclear NOE effect, controlled decoupling, off resonance spectra, DEPT and JMOD experiment.
-2D-NMR spectroscopy: 1H-1H scalar correlation COSY and TOCSY, 1H-13C HETCOR and HMQC correlation, 1H-13C long range HMBC correlation, 13C-13C INADEQUATE correlation. Dipolar correlation 1H-1H NOESY. - Reference texts
- 1. M. Silverstein, F.X. Webster e D.J. Kiemle, IDENTIFICAZIONE SPETTROMETRICA DI COMPOSTI ORGANICI, 3° Edizione, Casa Editrice Ambrosiana
2. M. Hesse, H. Meier, B. Zeeh, METODI SPETTROSCOPICI IN CHIMICA ORGANICA, 2a Edizione, EdiSES
3. A. Randazzo, GUIDA PRATICA ALLA INTERPRETAZIONE DI SPETTRI NMR, Loghia
4. Teacher Lectures - Educational objectives
- The aim of the course is to provide to the student the basic knowledge and the methodology necessary for the interpretation of mass spectra (MS), infrared spectra (IR) and nuclear magnetic resonance spectra (NMR) for the structural identification of organic and bioorganic molecules.
The student must be able to communicate clearly and with adequate language his knowledge and his ability to interpret the various spectra.
At the end of the course the student will be able to perform a complete structural and stereochemical characterization of organic and bioorganic molecules through the combined analysis of the spectra obtained with the various techniques.
The student must also be able to simulate the spectra of new molecules and to decide which methods are most useful to solve a particular structural problem. - Prerequisites
- Good knowledge on the structure and reactivity of organic compounds.
- Teaching methods
- The course is organized as follows:
-Lectures on all subjects of the course.
-Exercises on the interpretation of IR, NMR and Mass spectra, practical training with conducting exercises for the determination of the structure of organic and biorganic molecules.
- Practical laboratory exercise: determination of the structure of an organic molecule prepared in the laboratory by recording and interpreting the Mass , IR, 1H-NMR, 13-CNMR and 2D-NMR-spectra. - Other information
- Lectures frequency is recommended.
Practical laboratory frequency is required. - Learning verification modality
- The exam includes two tests
1. Written test aimed at ascertaining the interpretative abilities of IR, NMR and Mass spectra for the determination of the structure of an unknown molecule. Duration of the test 2 hours.
2. Oral exam: the oral exam consists of a discussion of about 30 minutes aimed at ascertaining the level of knowledge achieved by the student through closed stimulus questions with an open answer. - Extended program
- Mass spectrometry (MS): Introduction and fundamental concepts. The MS spectrometer. Physical principle. Instrumentation: sample introduction, ionizing sources, analyzers, detectors. EIMS spectrum analysis: types of ions generated. Molecular peak, base peak and peaks fragment. Isotopic peaks and molecular formula. Schemes of fragmentation and rearrangements of organic and bioorganic compounds and relevance for structural characterization purposes. Information deductible from a mass spectrum.
Infrared spectroscopy (IR): General introduction. Diatomic molecule as a harmonic oscillator. Basic equations. Anharmonic behavior. Physical meaning of the force constant. Absorption of infrared radiation. Polyatomic molecules. Vibrational degrees of freedom. Main stretching and deformation bands. Secondary bands of overtone and coupling. Group frequencies. IR Spectrum: general methods for sample preparation and registration of spectrum. Review of the characteristic and diagnostic frequencies for the identification of the main functional groups. Examination of the IR spectra of the main classes of organic compounds. Analysis of inductive and mesomeric effect on absorption bands, effect of ring size of cyclic compounds, solvent and inter-and intra-molecular hydrogen bond effects on the absorption bands of various functional groups. Interpretation of IR spectra of organic and bioorganic molecules of medium structural complexity.
Nuclear magnetic resonance spectroscopy (NMR): General introduction. Magnetic properties of nuclei. Macroscopic magnetization. Resonance conditions. Instrumentation. NMR signal generation: CW-NMR, Pulse-NMR. Relaxation processes. The NMR experiment.
-1H NMR spectroscopy: number and intensity of the signals, chemical shift. Spin-spin coupling, coupling constants, long-range coupling. Chemical equivalence and symmetry, magnetic equivalence, first order spectra and higher order spectra. Selective spin decoupling, nuclear overhauser effect (NOE). Solvent effect and shift reagents. Examples of 1H-NMR spectra interpretation for organic and bioorganic molecules of medium structural complexity.
-13C-NMR spectroscopy: Chemical shift. 1H-13C coupling, broadband decoupled spectra, heteronuclear NOE effect, controlled decoupling, relaxation times, coupling with other cores, OFF-resonance spectra, DEPT and JMOD experiments. Spectroscopy of other nuclei with spin 1/2: nitrogen-15, fluoro-19 and phosphorus-31
-2D NMR spectroscopy: sequence for a 2D experiment. Homonuclear scalar 1H-1H COSY and TOCSY correlation, heteronuclear 1H-13C HETCOR and HMQC correlation, 1H-13C long range HMBC correlation, 13C-13C INADEQUATE correlation. Dipolar correlation 1H-1H NOESY.
Examples on determination of the structure of organic and bioorganic molecules through the combined analysis of the spectra obtained with the various techniques.