CHE (Organic) P-503 : Organic spectroscopy (Semester 3 )

CHE(O) 503

Organic spectroscopy 

-M.SC Syllabus  Gujarat University 2021-22

Unit – I UV-Visible & IR Spectroscopy

UV-Visible Spectroscopy:

• Introduction, Principle, Selection rules for electronic transition, Electronic transitions, Solvent effects, Chromophore and auxochrome, Different shifts, Instrumentation, Applications, Problems based on dienes, enones, benzoyl derivatives

IR Spectroscopy:

• Introduction, Principle, Selection rule, Important group frequencies, Modes of vibration, Degree of freedom, Different peaks, Preparation method for samples, Instrumentation 

Unit-II 1H NMR and 13C NMR 
1H NMR:

1H NMR: 

• Introduction
• nuclear spin and magnetic nuclei,
• nuclear magnetic moment,
• Behaviour of a bar magnet in a magnetic field, 
• The NMR transition measuring the chemical shift,
• shielding and de shielding of magnetic nucleus,
•  chemical shifts in aliphatic and aromatic compounds,
• factors affecting chemical shift,
• Spin-spin splitting: effect of spin-spin splitting on the spectrum,
•  mechanism of spin-spin splitting,
•  chemical exchange,
•  coupling constants (cis/trans, allylic system and aromatic ring); application of spin-spin splitting to structure determination-geminal-, vicinal-, long-range coupling; factors influencing geminal and vicinal coupling.

• simplification of the complex PMR spectra-

1. Increasing field strength (high resolution spectra),
2.  Use of shift reagents,
3. Spin-spin decoupling (Double resonance), 
4. Proton exchange,
5. Deuterium exchange,
6.  Nuclear Over Hauser Effect (NOE) FT and two-dimensional NMR spectroscopy: principle of FT NMR- FIDs, Fourier transformation;  1 3C, 1 9F, 3 1P NMR-range of chemical shift values, spectra of typical examples; 2D NMR spectra- introduction and types of 2D techniques.

• 2D NMR Spectroscopy: Theory and Principles Of 2D NMR Spectroscopy (COSY); To interpret or to draw HOMCOR (1H-1H COSY, DQFCOSY, INADEQUATE),

13 CNMR:

• Introduction,
• Difficulties and solution for recording 13C- NMR spectra; recording of 13C-NMR spectra – scale, solvents, solvent signals and their positions, multiplicity, 

• 13C-1H coupling constant;  proton coupled and decoupled 13C spectra, broad band decoupling, off resonance technique;

• Chemical shifts in 13C spectra – chemical shift calculation for alkanes, alkenes and alkynes, chemical shift calculation in internal and terminal substituted compounds, aromatic compounds;

• To identify structure from 13C NMR data;

• Use of 13C spectra in differentiating compounds/isomers; 
• 13CDEPT Spectra – Differentiation in Primary, Secondary and Tertiary

Unit-III Mass spectrometry

• Introduction,
• Determination of molecular weight and formulae,
• Parent peak,
• Base peak, 
• Molecular ion peak,
• metastable peak,
• Ionization techniques (CI, FD, FAB, ESI, MALDI), 
• Fundamental fragmentation process,
• Fragmentation patterns of organic functional groups,
• Example of mass spectral fragmentation of organic compounds with respect to their structure determination. 

Unit-IV Problems/interpretation structure/structure determination based
 on UV, IR, 1H NMR, 13C NMR, Mass spectrometry.

• Spectral Problems Based on Combined Spectroscopy - DBE rules,
• Problems based on UV-Visible spectroscopy,
• Problems based on IR spectroscopy,
• Problems based on Mass spectrometry,
• Problems based NMR spectroscopy.

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Course Objectives:

1. To familiarize students with the most commonly used spectroscopic techniques.
2. Introduce basic and essential requirements to solve or understand the spectral problem.
3. Develop basic skills to interpret the spectra using spectroscopic data
4. To understand the basic spectroscopy of organic chemistry.
5. To understand the process and techniques of spectroscopy.
6. To learn the advancement of spectroscopy.
7. To understand the various techniques with advantages, disadvantages/limitations and application of spectroscopy in industrial aspects. 

Learning Outcome :

1. The students will understand the concept, importance and scope of UVVisible spectroscopy.
2. Evaluate the utility of UV/Vis spectroscopy as a qualitative and quantitative method.
3. The students will understand the concept and importance of IR spectroscopy.
4. The students will understand the role of infrared spectroscopy in the study of structure of organic compounds
5. The student will understand the concept and application of NMR ( 1 HNMR and 13CNMR) in organic synthesis as well as medicinal chemistry.
6. Students will learn fragmentation patterns by Mass spectroscopy.
7. To be able to analyze and interpret the spectral data collected from different spectroscopic techniques.
8. To be able to solve problems related to the structure, purity, and concentration of chemicals.
9. To gain valuable insight into the types of molecular interactions by choosing suitable spectroscopic methods and interpreting the obtained data.