Organic Chemistry II

Professor Carl C. Wamser

Chem 335 - Winter 2007

Chapter 13 Notes

Spectroscopy / Structure Determination

Determination of the Structure of Organic Compounds

Properties of Light

The Electromagnetic Spectrum

Absorption Spectroscopy

Molecular Energy Levels

Types of Molecular Energy

Nuclear Spin States

Nuclear Magnetic Resonance

NMR Instrumentation

MRI - Magnetic Resonance Imaging

Equivalent Hydrogens

Chemical Shifts

TMS as a Reference

Integrated Peak Areas

Chemical Shift Correlations

Spin-Spin Splitting Patterns

The (n+1) Rule

Coupling Constant, J (Hz)

C-13 NMR Spectra

Interpretation of NMR Spectra - Solving Puzzles

  1. How many absorptions are there?
    indicates number of equivalent kinds of Hs
  2. What are their intensities?
    indicates number of Hs of each type
  3. What are their chemical shifts?
    indicates the environment of each type of H
  4. What is the splitting pattern?
    indicates neighboring Hs

Infrared Spectroscopy

IR Spectra

Regions of an IR Spectrum

Interpreting an Unknown IR Spectrum

Ultraviolet/Visible Spectroscopy

Electronic Absorption Spectra

Photochemistry

Mass Spectrometry

Instrumental Operation

Mass Spectrum

Isotopes

Fragmentation Patterns

Interpretation of Mass Spectra