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IR spectroscopy and gas range

  1. Mar 21, 2015 #1
    Hi I was wondering if anyone could tell me what gasses are absorbed between 800 and 1000nm wavelength and weather there is a book that lists all the gas wavelengths that can be absorbed in this region
    Thanks bertopolis
  2. jcsd
  3. Mar 21, 2015 #2

    Quantum Defect

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    Not many gases absorb this far to the red. This wavelength range would be mostly electronic transitions of larger molecules. You don't see vibrational transitions until farther into the infrared. Iodine vapor absorbs in the visible, but I do not recall if there are transitions out this far.

    Most gases are small molecules. Small molecules have widely-spaced energy levels, and most small molecules do not absorb until you get into the ultraviolet energy range. Hideo Okabe wrote a very good book on the photochemistry of small molecules that has a useful table in the back. Gerhard Herzberg's books have useful compilations of data for many common molecules.

    There is a database of atmospheric spectra (HITRAN) that has been developed over the years.

    There are transitions between excited states of molecules that likely lie in this region, but you will need exotic methods to excite the gases.

    No doubt you can find some gas molecules that absorb here, but these will be very exotic species--not the common atmospheric species.
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