Chemical Sciences

NMR Spectroscopy. Electromagnetic spectrum. Basic theoretical concepts: the resonance phenomenon. Description of a FT-NMR experiment. Apparatuses and magnets types. Deuterated solvents. Shielding and deshielding phenomena. The chemical shift and its causes : inductive effects, diamagnetic anisotropy. Line width and integral of signals. Chemically equivalent and magnetically equivalent nuclei. Homotopic, enatiotopic, and diastereotopic protons. Spin-spin couplin. First-order spin systems: AX, AMX, AB etc. AA’XX’, AA’BB’, etc systems. Protons on heteroatoms. Hydrogen bond effect on chemical shift. How to simplify a NMR spectrum: using spectrometers with different field values, deuterating, using shift reagents, decoupling, NOE effect. Sample preparationd and spectrum acquisition. 1H NMR spectra and molecular structure. 13C NMR spectroscopy. Chemical shift, coupling. Outline of NMR spectroscopy in chemical kinetics. Dynamic NMR. IR Spectroscopy. Instruments. Sample preparation. Spectra interpretation. Group frequencies of organic functional groups. UV-visible Spectroscopy. Electronic transitions. Instruments. Solvent effect on UV-visible spectra, empirical parameters of solvent polarity, bathochromic and ipsochromic effect. Chromophores groups. Electronic transition in ketones and aromatic compounds. Outline of UV-visible spetroscopy in chemical kinetics. Mass spectrometry. Basic concepts of mass spectrometry. Instruments and spectra registration. Molecular Parent peak, base peak, isotopic peaks. Degree of unsaturations rule. Outline of the more common fragmentations: alpha cleavage, benzylic and allylic cleavage, cleavage of non-activated bonds. Other Ionization methods: CI, DCI, ESI, FAB. Outline of GC-MS technique and of Tandem mass Practical approach to the NMR, IR, UV-visible and mass spectra interpretation aimed to establish the structure of simple organic compounds. Students will also perform laboratory experiments concerning simple synthesis of organic compounds. Purification methods: Extraction (solubility and structure, pH effect on solubility, partition coefficient). Distillations (simple and fractionate distillation, azeotropes), Crystallization and filtration. Chromatography (physical principles, TLC and spot detection, column chromatography). Safety in organic chemistry lab. Each laboratory exercise will be preceded by a description in the classroom.

No prerequisites.

- "Identificazione spettroscopica di composti organici" di R. M. Silverstein e F. X. Webster Casa Editrice Ambrosiana. - "Metodi spettroscopici nella chimica organica" di M. Hesse, H. Meier, B. Zeeh Casa Editrice EdiSES

Not mandatory

The final exam aims to verify the following learning skills: determination of the structure of organic compounds through the interpretation of their spectra (NMR, mass, IR, UV-vis) discussing the reasoning performed and motivating the choice of the structure, and illustration of the reactions of organic synthesis carried out in the laboratory. The exam consists of passing a written exam consisting in the analysis of a set of spectra of an unknown substance and an oral interview on the topics of the course and laboratory reports, and discussion of the structure identified in the written test. It also consists in the in-depth discussion of one of the reactions conducted in the teaching laboratory.

The course consists of lectures and laboratory experiences.

NMR Spectroscopy: Basic theorical concepts: Electromagnetic spectrum. Resonance phenomenon (spin orientation in a magnetic field, Larmor precession, interaction with electromagnetic waves, quantization, macroscopic magnetization, relaxation T1 and T2, NMR signal and its width). Presentation of a typical NMR experiment. Instrumentation and magnets. Deuterated solvents, Sample preparation. Chemical shift: 1H-NMR spectrum and molecular structure. Factors affecting chemical shift: hybridization, inductive effects, diamagnetic anisotropy, substituents. Typical shift of common functional groups. Line width and area (integral). Chemical equivalence. Homotopic, enantiotopic and diastereotopic protons. Spin-spin coupling: Physical principles. Vicinal, geminal and long-range coupling. Karplus relations. First order spin systems: AX, AMX, AB etc. AA’XX’, AA’BB’ systems etc. Magnetic equivalence. Basic concepts on higher order spin systems and typical patterns. Chemical exchange. Theorical concepts. Protons on heteroatoms. Influence of hydrogen bonding on chemical shift and signal shape. Dynamic NMR. Theorical concepts. Slow and Fast exchange, coalescence. NMR timescale and influence of temperature. Introduction to the use of NMR spectroscopy in kinetics. Strategies to simplify NMR spectra: use of different instrumentation, deuteration, shift reagents, decoupling, NOE effect. 13C-NMR Spectroscopy. Physical principles, recording of spectra, Chemical shift, coupling. IR Spectroscopy. Physical principles (vibrational modes and frequencies, assignment of these modes). Instrumentation. Sample preparation. Typical absorbance of common functional groups. UV-Vis Spectroscopy. Physical principles. Electronic transitions (transition types, wavelengths and intensity). Instrumentation. Chromophore and auxochrome groups. Color and conjugation. Electronic transitions in aromatics and carbonyl compounds. pH effect. Solvent effect. Intro Mass spectrometry. Key concepts. Ionization methods (EI, CI, FAB, ESI, MALDI). Ion separation methods (magnetic sector, quadrupole, TOF). Recording of spectra. Interpretation of MS spectra: Molecular peak, base peak, isotope peaks. Resolution. Unsaturation rule. Introduction to main fragmentations: alfa cleavage, benzylic and allylic cleavage, McLafferty rearrangement. Interpretation of NMR, IR, UV-Vis and MS spectra for the identification of organic compounds. Organic Chemistry Lab. Typical syntheses of organic compounds (Reaction, workup, analysis). - Purification methods: Extraction (solubility and structure, pH effect on solubility, partition coefficient). Distillations (simple and fractionate distillation, azeotropes), Crystallization and filtration. Chromatography (physical principles, TLC and spot detection, column chromatography) - Laboratory practices: Synthesis and purification of simple organic compounds. Safety in organic chemistry lab.

None

- "Identificazione spettroscopica di composti organici" di R. M. Silverstein e F. X. Webster Casa Editrice Ambrosiana. - "Metodi spettroscopici nella chimica organica" di M. Hesse, H. Meier, B. Zeeh Casa Editrice EdiSES.

Attendance at lectures is optional. Attendance at laboratory experiences is mandatory (maximum one absence).

The exam will verify these skills: determination of the structure of an unknown organic compound via interpretation of spectra (NMR, UV, IR, MS) discussing the logic path followed and motivating the proposed structure, in-depth presentation and discussion of the organic reactions involved in the laboratory practices. The exam is divided into two parts: a written exercise (analysis of a set of spectra of an unknown compound to identify its structure) and an oral discussion on the analysis performed in the written exercise, on the course topics and a detailed discussion of one laboratory practice.

The course consists of lectures and laboratory practices.

NMR Spectroscopy: Basic theorical concepts: Electromagnetic spectrum. Resonance phenomenon (spin orientation in a magnetic field, Larmor precession, interaction with electromagnetic waves, quantization, macroscopic magnetization, relaxation T1 and T2, NMR signal and its width). Presentation of a typical NMR experiment. Instrumentation and magnets. Deuterated solvents, Sample preparation. Chemical shift: 1H-NMR spectrum and molecular structure. Factors affecting chemical shift: hybridization, inductive effects, diamagnetic anisotropy, substituents. Typical shift of common functional groups. Line width and area (integral). Chemical equivalence. Homotopic, enantiotopic and diastereotopic protons. Spin-spin coupling: Physical principles. Vicinal, geminal and long-range coupling. Karplus relations. First order spin systems: AX, AMX, AB etc. AA’XX’, AA’BB’ systems etc. Magnetic equivalence. Basic concepts on higher order spin systems and typical patterns. Chemical exchange. Theorical concepts. Protons on heteroatoms. Influence of hydrogen bonding on chemical shift and signal shape. Dynamic NMR. Theorical concepts. Slow and Fast exchange, coalescence. NMR timescale and influence of temperature. Introduction to the use of NMR spectroscopy in kinetics. Strategies to simplify NMR spectra: use of different instrumentation, deuteration, shift reagents, decoupling, NOE effect. 13C-NMR Spectroscopy. Physical principles, recording of spectra, Chemical shift, coupling. IR Spectroscopy. Physical principles (vibrational modes and frequencies, assignment of these modes). Instrumentation. Sample preparation. Typical absorbance of common functional groups. UV-Vis Spectroscopy. Physical principles. Electronic transitions (transition types, wavelengths and intensity). Instrumentation. Chromophore and auxochrome groups. Color and conjugation. Electronic transitions in aromatics and carbonyl compounds. pH effect. Solvent effect. Intro Mass spectrometry. Key concepts. Ionization methods (EI, CI, FAB, ESI, MALDI). Ion separation methods (magnetic sector, quadrupole, TOF). Recording of spectra. Interpretation of MS spectra: Molecular peak, base peak, isotope peaks. Resolution. Unsaturation rule. Introduction to main fragmentations: alfa cleavage, benzylic and allylic cleavage, McLafferty rearrangement. Interpretation of NMR, IR, UV-Vis and MS spectra for the identification of organic compounds. Organic Chemistry Lab. Typical syntheses of organic compounds (Reaction, workup, analysis). - Purification methods: Extraction (solubility and structure, pH effect on solubility, partition coefficient). Distillations (simple and fractionate distillation, azeotropes), Crystallization and filtration. Chromatography (physical principles, TLC and spot detection, column chromatography) - Laboratory practices: Synthesis and purification of simple organic compounds. Safety in organic chemistry lab

- "Identificazione spettroscopica di composti organici" di R. M. Silverstein e F. X. Webster, 3° Edizione, Casa Editrice Ambrosiana, 2016. - "Metodi spettroscopici nella chimica organica" di M. Hesse, H. Meier, B. Zeeh, 2° Edizione, Casa Editrice EdiSES, 2008

Attendance at lectures is optional. Attendance at laboratory experiences is mandatory (maximum one absence).

The exam will verify these skills: determination of the structure of an unknown organic compound via interpretation of spectra (NMR, UV, IR, MS) discussing the logic path followed and motivating the proposed structure, in-depth presentation and discussion of the organic reactions involved in the laboratory practices. The exam is divided into two parts: a written exercise (analysis of a set of spectra of an unknown compound to identify its structure) and an oral discussion on the analysis performed in the written exercise, on the course topics and a detailed discussion of one laboratory practice

The course consists of lectures and laboratory practices