CY6013 : Spectroscopy-Applications in Organic Chemistry

Course Objectives: To learn basic principles of NMR, IR, UV-Vis spectroscopy and mass spectrometry and to use these spectroscopic methods for organic structure elucidation.

Learning Outcomes: At the end of the course, the learners should be able to:

Apply NMR, IR, MS, UV-Vis spectroscopic techniques in solving structure of organic molecules and in determination of their stereochemistry.

Interpret the above spectroscopic data of unknown compounds.

Use these spectroscopic techniques in their research.

Course Contents:

NMR Spectroscopy: NMR phenomenon, spin ½ nuclei, (1H, 13C, 31P and 19F), 1H NMR, Zeeman splitting, effect of magnetic field strength on sensitivity and resolution, chemical shift d, inductive and anisotropic effects on d, chemical structure correlations of d, chemical and magnetic equivalence of spins, spin-spin coupling, structural correlation to coupling constant J, first order patterns. Second order effects, examples of AB, AX, AA’BB’ and ABX systems, simplification of second order spectrum, application of NMR data for stereochemical assignments, selective decoupling, use of chemical shift reagents for stereochemical assignments. 13C NMR, introduction to FT technique, relaxation of nuclear spins, NOE effects, 1H and 13C chemical shifts to structure correlations. Study of dynamic processes by VT NMR, restricted rotation (DMF, DMA, biphenyls, annulenes), cyclohexane ring inversion, degenerate rearrangements (bullvalene and related systems).

Application of DEPT technique to the analysis of CH multiplicities in 13C NMR spectroscopy.

Correlation spectroscopy: Illustration of practical applications of 1H-1H COSY, 1H-13C COSY, NOE difference spectroscopy (Stereochemistry determination), HMQC and HSQC techniques.

Electronic spectroscopy, basic principle, electronic transitions in organic, and molecules and application to structure elucidation. Optical rotatory dispersion and circular dichroism (ORD and CD) spectroscopy, underlying principle, Plane curves, Cotton effects, octant rule, axial halo-keto rule, applications to assignment of configuration of chiral molecules. Infrared spectroscopy: organic functional group identification through IR spectroscopy.

Mass spectrometry:, basic principles, ionization techniques, isotope abundance, molecular ion, fragmentation processes of organic molecules, deduction of structure through mass spectral fragmentation, high resolution MS, soft ionization methods, ESI-MS and MALDI-MS, basic principle of ionization and ion analysis, illustrative examples from simple organic molecules to macromolecules and supramolecules.

Structure elucidation problems using the above spectroscopic techniques.

Text Books:

  1. Gunther, NMR Spectroscopy, 2nd ed.; John Wiley and Sons, 1995.
  2. L. Pavia, G. M. Lampman, G. S. Kriz, J. R. Vyvyan, Spectroscopy, Cengage Learning, New Delhi, 2007.
  3. Kemp, Organic Spectroscopy, 2nd edition, ELBS-Macmillan, 1987.
  4. D. W. Claridge, High-Resolution NMR Techniques on Organic Chemistry, Pergamon, New York, 1999.
  5. S. Macomber, A Complete Introduction to Modern NMR Spectroscopy, R. S. Macomber, Wiley, 1997.
  6. For CD and ORD: D. Nasipuri, Stereochemistry of Organic Compounds, Principles and Applications, New Age International, New Delhi, 2011, chapter 15.