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Xenon oxide photochemical preparation?

  1. Sep 10, 2012 #1
    In 1994 I attended a symposium at University College London to celebrate the centenary of William Ramsay's discovery of argon. In a rather remarkable presentation there some slides were shown of some beautiful clear large crystals in a sealed quartz flask.

    If my memory is not playing tricks on me, I think the lecturer said something even more surprising: that the crystals were the result of leaving an equimolar mixture of xenon and oxygen in the flask to be irradiated in strong sunlight in the middle of a sports field. After the photographs were taken the flask was destroyed by throwing stones at it, because the product, an oxide of xenon, was too unstable and explosive to be safely handled in the flask.

    It is a long shot, but has anyone else a lead on this experiment? A publication? A similar lecture? Some detail that I might have got wrong? I have failed to find anything like it, but would rather like to have a reference.
     
  2. jcsd
  3. Sep 11, 2012 #2
    Apologies to all. I think I must have misremembered -- have discovered that xenon difluoride can be prepared in an exactly analogous way to what I have described with a mixture of xenon and fluorine gases.

    Will leave this thread open just in case anyone does have information about a direct reaction between xenon and oxygen.
     
  4. Sep 16, 2012 #3

    AGNuke

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    I had read that Xenon do not react directly with Oxygen. Instead, Oxides of Xenon are obtained by reacting fluorides of Xenon with Oxygen.
     
  5. Sep 16, 2012 #4
    Yes AGNuke, that is certainly the received textbook wisdom.

    I did have a purpose in asking specifically about the direct reaction. For many years I have wondered why high pressure xenon lamps occasionally explode with a violence that seems extreme, even allowing for a high working temperature and high internal pressure in the quartz envelope. These lamps are often used as continuous sources of intense UV radiation in photochemical studies.

    Was wondering about the possibility of buildup of unstable explosive xenon oxides where the two gases could come into contact in microcracks in a quartz envelope.
     
  6. Sep 17, 2012 #5

    AGNuke

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    Here's what I think of your assertion. According to another divine textbook wisdom, Xenon Short Arc Lamps has high spectral emission in Ultra-Violet region. And it doesn't require explanation what happens to O2 when it is exposed to UV.

    Now, if the oxygen diffuses inside the quartz envelope due to some defects or something like that, Ozone will come in direct contact with the Xenon Gas. Correct me here, but I think that Ozone is one of the strongest oxidizing agents, just falling short of Fluorine, which can oxidize Xenon on its own, so why not Ozone?

    Then what, for a moment, XeO3 or XeO4 can be formed, both of which are very explosive even at room temperature, let alone at the temperature attained in the Xenon Lamps. Then no need to tell what will happen.

    This is the best reasoning I can come up with. I don't know anything about Xenon chemistry. In fact, I only learned 12th grade chemistry in my country, so I don't know whether my "hypothesis" stands or not.
     
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