| CODE | CHE2362 | ||||||||||||
| TITLE | Organic Spectroscopy | ||||||||||||
| UM LEVEL | 02 - Years 2, 3 in Modular Undergraduate Course | ||||||||||||
| MQF LEVEL | 5 | ||||||||||||
| ECTS CREDITS | 4 | ||||||||||||
| DEPARTMENT | Chemistry | ||||||||||||
| DESCRIPTION | 1. Introduction: Methods used to characterise organic/inorganic compounds. Brief overview of IR, UV, & NMR spectroscopy, Mass spectrometry, X-ray crystallography, and elemental analysis. 2. Infrared Spectroscopy: Theory: Region of interest in the electromagnetic spectrum; units; definition of stretching and bending modes of vibration; IR active/IR inactive (Raman) modes; vibrational degrees of freedom of a linear & non-linear molecule; CO2, H2O, CH2; definition of degenerate, combination, and overtone bands; simple application of Hooke's law to predict IR frequencies; isotope effects. Instrumentation: Block diagram of a conventional (scanning) IR spectrometer, including a brief description of components and their functions; modern FTIR - brief overview including advantages; sample handling and preparation, including demonstration of cells used - gasses, liquids and solids. Interpretation of spectra: Areas of primary interest - functional group and fingerprint regions; IR spectra of different classes of compounds with examples - Alkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, phenols, ethers, ketones, aldehydes, conjugated carbonyls, carboxylic acids - H-bonding effects, carboxylate, esters, anhydrides, amides, amines, nitriles, nitro group, and halides. 3. Ultraviolet Absorption Spectroscopy: Theory: Origin of UV absorption; electronic transitions; molecular orbitals; δ→π*, n→δ*, n→π*, π→π*, relationship between energy and frequency; quantum nature of absorption; appearance of UV Beer-Lambert law and quantitative UV spectroscopy; terminology - R, K, B, & E bands; definition of chromophore, auxochrome, batho- hypso-, hyper-, and hypochromic shifts; characteristics of n→π* and π→π* bands, including solvent effects. Instrumentation: Block diagram, describing components and their functions; sample handling and cell requirements; typical procedure for the measurement of UV spectra of unknown compounds; useful solvents. Characteristic UV spectra of organic compounds: Saturated hydrocarbons; ethylenic chromophores - alkenes, conjugated dienes, homo- and heteroannular dienes, Fieser rules for prediction of λmax, carbonyl chromophores, substituent effects, B-diketones, α, ß-unsaturated carbonyls, Woodward rules, aromatic compounds, benzene, substituted benzenes, auxochromic effects, phenols and anilines, isosbestic point,conjugated aromatics, and polynuclear aromatic hydrocarbons. 4. Mass Spectrometry: Instrumentation and use: Block diagram of components and their functions; low and high resolution mass spectrometers; data presentation; molecular ions; base peaks; isotope peaks; determination of molecular formulae; the nitrogen rule; rules for predicting major fragmentation modes. Characteristic mass spectra: Saturated hydrocarbons; alkenes; aromatics; alcohols; ethers; ketones; aldehydes; the McLafferty rearrangement; carboxylic acids, esters, amines, amides, and halogen compounds. 5. Theory of Nuclear Magnetic Resonance (NMR) phenomena: Spin quantum numbers. Conditions for resonance, and relation to field strengths. Equilibrium and relaxation processes. Instrumentation. Field-and frequency sweep spectra. Sample requirements. Chemical shifts, definition and theory. High resolution NMR. Presentation of data and terminology. Shielding. Ring currents. Resonance of aromatic, alkene, and alkyne protons. Theory and magnitude of spin-spin coupling. Geminal and vicinal protons. Splitting patterns. Pascal's triangle and the N+1 rule. Non first-order spectra. Coupling to non-equivalent neigbours. Protons on hetero-atoms. Deuterium exchange. Cis/trans and long-range coupling. Typical spectra of substituted aromatics. Spin-spin decoupling techniques. ¹³C NMR. Problems and advantages. Brief FT NMR theory and instrumentation. ¹³C chemical shifts and coupling constants. Broad band and off-resonance decoupling. Integration in ¹³C spectra. Examples in interpretation of ¹H and ¹³C spectra. Study-unit Aims: The aims of this study-unit are to introduce the students to the principles of IR, UV, NMR and Mass Spectrometry and how these can be used in the identification of organic compounds. Learning Outcomes: 1. Knowledge & Understanding: By the end of the study-unit the student will be able to: - Appreciate what is required in order to report the syntheses of new organic compounds in the literature; - Understand the principles of Infrared (IR) Spectroscopy, including instrumentation and sample preparation; - Interpret IR spectra in terms of deducing which functional groups are present; - Understand the principles of Ultraviolet-Visible (UV-Vis) Spectroscopy, including instrumentation and sample preparation; - Interpret UV-Vis spectra in terms of deducing which chromophores are present; - Understand the principles of Mass Spectrometry (MS), including instrumentation; - Interpret Mass spectra in terms of deducing the identity of fragment and or rearrangement peaks, and thus infer the structure of the molecular ion; - Understand the principles of Nuclear Magnetic Resonance (NMR) spectroscopy, including instrumentation and sample preparation; - Interpret 1H and 13C NMR spectra in terms of deducing what functional groups are present (chemical shift) and the number of them present (integration). 2. Skills: By the end of the study-unit the student will be able to analyse any combination of IR,UV-Vis, MS, and NMR data, and provide a rational interpretation that leads them to suggest a plausible structure for the (unknown) organic compound responsible for that data. Main Text/s and any supplementary readings: (availability at the Library or otherwise is indicated against each entry) Robert M. Silverstein, Francis X. Webster, David Kiemle., Spectrometric Identification of organic compounds, 7th Edition (Wiley, 2005). ISBN: 978-0-471-39362-7. (Available in the Library). Vollhardt, K. Peter C., Schore, Neil E., Organic Chemistry, Structure and Function. [5th ed., 2007] W. H. Freeman & Co. ISBN: 7167-9949-9. (Available in the Library). |
||||||||||||
| ADDITIONAL NOTES | Pre-Requisite Study-Unit: CHE1360 | ||||||||||||
| STUDY-UNIT TYPE | Lecture | ||||||||||||
| METHOD OF ASSESSMENT |
|
||||||||||||
| LECTURER/S | |||||||||||||
|
The University makes every effort to ensure that the published Courses Plans, Programmes of Study and Study-Unit information are complete and up-to-date at the time of publication. The University reserves the right to make changes in case errors are detected after publication.
The availability of optional units may be subject to timetabling constraints. Units not attracting a sufficient number of registrations may be withdrawn without notice. It should be noted that all the information in the description above applies to study-units available during the academic year 2024/5. It may be subject to change in subsequent years. |
|||||||||||||