Molecular Spectroscopy

    Eitam Vinegrad, Instructor of the molecular fluorescence experiment Multi-disciplinary building, room 210. 03-6408628


         The experiment is performed at Lab 3, Shenkar Physics building.



  1. Introduction
  2. Topics of the experiment
  3. How to prepare for the experiment?
  4. The experimental schedule
  5. Literature
  6. Links


Molecular spectroscopy is a method to study the molecular structure of gases, liquids and solids.  It is based on the fact that vibration and rotation of the atoms inside a molecule has discreet energy levels. If light passes through the material in the exact frequency it will be absorbed.

Using a light source, an optical apparatus, an interferometer and an optical fiber we are able to measure the absorbance and transmittance of infra-red light in the substance. From that we will deduce the inter-molecular structure and properties of the substance.

Molecular spectroscopy (also called FTIR Fourier Transform Infra Red spectroscopy) is used in many fields today: Medicine to detect Cancer, Pollution control and detection of poisons in real time, for the food industry research in many fields and for chemistry - process control and molecular analysis.

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Topics of the experiment

  1. Learning to use a modern FTIR spectrometer.
  2. Learning to identify substances by spectrum. 
  3. Using spectral analyses to calculate molecular properties.
  4. Follow your interests Your own privet experiment.

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How to prepare for the experiment?

  1. Contact the Instructor.
  2. Read the experiment's instructions.
  3. Read the Theory File.
  4. Make sure you understand the experimental technique.
  5. Understand the terms (in the experimental file).
  6. Read the Lab's safety instructions.

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The experimental schedule

  1. Written exam - Approximately one hour.
  2. Equipment and Methods overview.
  3. Thin films measurements.
  4. CO & CO2 measurements.
  5. Liquid Concentration measurements using ATR.
  6. Your project!

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  1. Lab instruction (DOC).
  2. Theory (PDF) or Theory (DOC)
  3. Water article summary(PDF)
  4. lab data concerning HCl/CO model (PDF)
  5. lab data concerning cigarette smoke analysis (PDF)

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  1. How to write a report

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