CHEM61201 Spectroscopic Techniques

Unit code: CHEM61201
Credit Rating: 15
Unit level: Level 6
Teaching period(s): Semester 1

Aims

  • To explore further aspects of the theory of molecular spectroscopy, mass spectrometry and chromatography, as applied in analytical chemistry labs to small molecules.
  • To further practice the interpretation of spectra and chromatograms, and to use a synthesis of data from a number of methods to identify unknown molecules.
  • To practice multispectral interpretation in a supportive, workshop setting in order to develop analytical chemistry skills for practical labs and projects.

Overview

Molecular spectroscopy, chromatography and mass spectrometry are fundamental to chemical analysis and are important tools in all areas of chemistry. In this module, further principles and applications of some of the most common techniques will be presented, building upon ideas and concepts developed in the first year. The prime objective of the module is to present an integrated, coherent discussion of chemical identification using chromatography and a combination of spectra, as practised in modern synthetic and analytical chemistry laboratories.

 

The module will include the modern theory and practice of:

 

  • High liquid and gas performance chromatography
    • Theory of chromatography, from partition equilibrium to the van Deemter equation
    • Integration of chromatography with other instrumentation (e.g. GC-MS, LC-MS)
    • Mass spectrometry
      • Its basic operating principles, including the methods of generating ions
      • Interpretation of mass spectra, based on the ionisation method
      • High resolution mass spectrometry for determination of molecular formula
    • Infrared and Raman spectroscopy
      • Introduction to Raman spectroscopy (theory and practice), and comparison to infrared absorption spectra
      • Identification of functional groups in vibrational spectra
    • Nuclear magnetic resonance spectroscopy
      • Its basic operating principles and basics of nuclear magnetic spin
      • Interpretation of 1H and 13C NMR spectra
      • Use and interpretation of two dimensional NMR (2D-NMR) spectra
      • Interpretation of other spin I = ½ and non I = ½ nuclei in NMR (“multinuclear NMR”); multiple splittings from I = ½ and non I = ½ nuclei; low-abundance spin-active nuclei; satellites.
      • Dynamic NMR; in organic and inorganic applications.

Assessment methods

Written exam - 100%

 

Learning outcomes

Students successfully completing this unit should have developed the ability to:

  • describe the physical processes employed in chromatography, i.e. adsorption, desorption, the van Deemter A,B and C terms, sample injection, gas flow, liquid flow and eluate detection;
  • discuss the nature of chromatographic columns, including normal and reverse phases, and outline procedures for choosing columns and solvent systems;
  • identify the main components of commercial GC and HPLC instrumentation, and describe the coupling of mass spectrometric detection to GC and LC methods;
  • describe the mode of operation of a mass spectrometer and interpret simple mass spectra (parent ions, major fragments) for small molecules;
  • describe the basis of Raman scattering and its use as a spectroscopic tool;
  • interpret simple pure-compound infrared and Raman spectra on the basis of group modes and fingerprint spectra, and correlate these with other spectroscopic data;
  • describe the basis of 1H NMR spectroscopy (including spin-spin coupling) and to interpret simple pure-compound NMR spectra;
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